अनुक्रम \(4,9,14,19,\ldots\) का सामान्य पद क्या है?
What is the general term of the sequence \(4,9,14,19,\ldots\)?
#sequences
#progressions
#explicit-rule
#class-9
#medium
50 50-50 2 wrong hide
⏭ Skip Next question
+10 Time+ 10 sec extra
? Hint Small clue
A \(a_n=5n+1\)
B \(a_n=5n-1\)
C \(a_n=4n+5\)
D \(a_n=n+4\)
Explanation opens after your attempt
Correct Answer
B. \(a_n=5n-1\)
Step 1
Concept
The first term is (4) and the difference is (5), so \(a_n=5n-1\). In exams, always check the first term by putting (n=1).
Step 2
Why this answer is correct
The correct answer is B. \(a_n=5n-1\). The first term is (4) and the difference is (5), so \(a_n=5n-1\). In exams, always check the first term by putting (n=1).
Step 3
Exam Tip
पहला पद (4) और अंतर (5) है, इसलिए \(a_n=5n-1\) है। परीक्षा में (n=1) रखकर पहला पद जरूर जाँचें।
Login to save your score, XP, coins and progress. Login
यदि \(a_n=7n-3\) है, तो \(a_8\) का मान क्या होगा?
If \(a_n=7n-3\), what is the value of \(a_8\)?
#sequences
#progressions
#explicit-rule
#class-9
#medium
50 50-50 2 wrong hide
⏭ Skip Next question
+10 Time+ 10 sec extra
? Hint Small clue
A (49)
B (51)
C (52)
D (53)
Explanation opens after your attempt
Step 1
Concept
\(a_8=7\times8-3=53\). In exams, subtract only after multiplying.
Step 2
Why this answer is correct
The correct answer is D. (53). \(a_8=7\times8-3=53\). In exams, subtract only after multiplying.
Step 3
Exam Tip
\(a_8=7\times8-3=53\) है। परीक्षा में गुणा के बाद ही घटाव करें।
Login to save your score, XP, coins and progress. Login
अनुक्रम \(12,19,26,33,\ldots\) के लिए सही स्पष्ट नियम कौन-सा है?
Which explicit rule is correct for the sequence \(12,19,26,33,\ldots\)?
#sequences
#progressions
#explicit-rule
#class-9
#medium
50 50-50 2 wrong hide
⏭ Skip Next question
+10 Time+ 10 sec extra
? Hint Small clue
A \(a_n=7n+5\)
B \(a_n=12n\)
C \(a_n=7n-5\)
D \(a_n=5n+7\)
Explanation opens after your attempt
Correct Answer
A. \(a_n=7n+5\)
Step 1
Concept
The difference is (7), and at (n=1) the value must be (12), so \(a_n=7n+5\). In exams, take the difference as the coefficient of (n).
Step 2
Why this answer is correct
The correct answer is A. \(a_n=7n+5\). The difference is (7), and at (n=1) the value must be (12), so \(a_n=7n+5\). In exams, take the difference as the coefficient of (n).
Step 3
Exam Tip
अंतर (7) है और (n=1) पर मान (12) चाहिए, इसलिए \(a_n=7n+5\) है। परीक्षा में अंतर को (n) का गुणांक मानें।
Login to save your score, XP, coins and progress. Login
यदि \(a_n=50-4n\) है, तो \(a_9\) का मान क्या होगा?
If \(a_n=50-4n\), what is the value of \(a_9\)?
#sequences
#progressions
#explicit-rule
#class-9
#medium
50 50-50 2 wrong hide
⏭ Skip Next question
+10 Time+ 10 sec extra
? Hint Small clue
A (10)
B (12)
C (14)
D (16)
Explanation opens after your attempt
Step 1
Concept
\(a_9=50-36=14\). In exams, subtract (4n) correctly in a decreasing formula.
Step 2
Why this answer is correct
The correct answer is C. (14). \(a_9=50-36=14\). In exams, subtract (4n) correctly in a decreasing formula.
Step 3
Exam Tip
\(a_9=50-36=14\) है। परीक्षा में घटते सूत्र में (4n) को सही घटाएँ।
Login to save your score, XP, coins and progress. Login
अनुक्रम \(42,37,32,27,\ldots\) का सामान्य पद क्या है?
What is the general term of the sequence \(42,37,32,27,\ldots\)?
#sequences
#progressions
#explicit-rule
#class-9
#medium
50 50-50 2 wrong hide
⏭ Skip Next question
+10 Time+ 10 sec extra
? Hint Small clue
A \(a_n=42-5n\)
B \(a_n=47-5n\)
C \(a_n=5n+37\)
D \(a_n=47+n\)
Explanation opens after your attempt
Correct Answer
B. \(a_n=47-5n\)
Step 1
Concept
At (n=1) it gives (42), and at (n=2) it gives (37), so \(a_n=47-5n\). In exams, always match the first term in a decreasing sequence.
Step 2
Why this answer is correct
The correct answer is B. \(a_n=47-5n\). At (n=1) it gives (42), and at (n=2) it gives (37), so \(a_n=47-5n\). In exams, always match the first term in a decreasing sequence.
Step 3
Exam Tip
(n=1) पर (42) और (n=2) पर (37) मिलता है, इसलिए \(a_n=47-5n\) है। परीक्षा में घटते अनुक्रम में पहला पद जरूर मिलाएँ।
Login to save your score, XP, coins and progress. Login
यदि \(a_n=3n+2\) है, तो कौन-सा पद (38) के बराबर होगा?
If \(a_n=3n+2\), which term will be equal to (38)?
#sequences
#progressions
#explicit-rule
#class-9
#medium
50 50-50 2 wrong hide
⏭ Skip Next question
+10 Time+ 10 sec extra
? Hint Small clue
A (n=9)
B (n=10)
C (n=11)
D (n=12)
Explanation opens after your attempt
Step 1
Concept
From (3n+2=38), we get (n=12). In exams, equate the formula to the given value when term number is asked.
Step 2
Why this answer is correct
The correct answer is D. (n=12). From (3n+2=38), we get (n=12). In exams, equate the formula to the given value when term number is asked.
Step 3
Exam Tip
(3n+2=38) से (n=12) मिलता है। परीक्षा में पद संख्या पूछी जाए तो सूत्र को दिए मान के बराबर रखें।
Login to save your score, XP, coins and progress. Login
अनुक्रम \(5,8,11,14,\ldots\) में (32) कौन-सा पद है?
In the sequence \(5,8,11,14,\ldots\), which term is (32)?
#sequences
#progressions
#explicit-rule
#class-9
#medium
50 50-50 2 wrong hide
⏭ Skip Next question
+10 Time+ 10 sec extra
? Hint Small clue
A आठवाँ पद / (8)th term
B नौवाँ पद / (9)th term
C दसवाँ पद / (10)th term
D ग्यारहवाँ पद / (11)th term
Explanation opens after your attempt
Correct Answer
C. दसवाँ पद / (10)th term
Step 1
Concept
Its rule is \(a_n=3n+2\), and (3n+2=32) gives (n=10). In exams, form the general term first to find the term number.
Step 2
Why this answer is correct
The correct answer is C. दसवाँ पद / (10)th term. Its rule is \(a_n=3n+2\), and (3n+2=32) gives (n=10). In exams, form the general term first to find the term number.
Step 3
Exam Tip
इसका नियम \(a_n=3n+2\) है और (3n+2=32) से (n=10) है। परीक्षा में पहले सामान्य पद बनाकर पद संख्या निकालें।
Login to save your score, XP, coins and progress. Login
अनुक्रम \(4,9,16,25,\ldots\) का सामान्य पद क्या है?
What is the general term of the sequence \(4,9,16,25,\ldots\)?
#sequences
#progressions
#explicit-rule
#class-9
#medium
50 50-50 2 wrong hide
⏭ Skip Next question
+10 Time+ 10 sec extra
? Hint Small clue
A (a_n=(n+1)2 )
B \(a_n=n^2\)
C \(a_n=n^2+1\)
D \(a_n=2n^2\)
Explanation opens after your attempt
Correct Answer
A. (a_n=(n+1)2 )
Step 1
Concept
These terms are \(2^2,3^2,4^2,5^2\), so (a_n=(n+1)2 ). In exams, recognize shifted square numbers.
Step 2
Why this answer is correct
The correct answer is A. (a_n=(n+1)2 ). These terms are \(2^2,3^2,4^2,5^2\), so (a_n=(n+1)2 ). In exams, recognize shifted square numbers.
Step 3
Exam Tip
ये पद \(2^2,3^2,4^2,5^2\) हैं, इसलिए (a_n=(n+1)2 ) है। परीक्षा में वर्ग संख्याओं के स्थानांतरण को पहचानें।
Login to save your score, XP, coins and progress. Login
यदि (a_n=(n+1)2 ) है, तो \(a_6\) का मान क्या होगा?
If (a_n=(n+1)2 ), what is the value of \(a_6\)?
#sequences
#progressions
#explicit-rule
#class-9
#medium
50 50-50 2 wrong hide
⏭ Skip Next question
+10 Time+ 10 sec extra
? Hint Small clue
A (36)
B (49)
C (64)
D (81)
Explanation opens after your attempt
Step 1
Concept
(a_6=(6+1)2 =49). In exams, find the value inside the bracket first and then square it.
Step 2
Why this answer is correct
The correct answer is B. (49). (a_6=(6+1)2 =49). In exams, find the value inside the bracket first and then square it.
Step 3
Exam Tip
(a_6=(6+1)2 =49) है। परीक्षा में पहले कोष्ठक का मान निकालें और फिर वर्ग करें।
Login to save your score, XP, coins and progress. Login
अनुक्रम \(2,6,12,20,\ldots\) के लिए सही सामान्य पद कौन-सा है?
Which general term is correct for the sequence \(2,6,12,20,\ldots\)?
#sequences
#progressions
#explicit-rule
#class-9
#medium
50 50-50 2 wrong hide
⏭ Skip Next question
+10 Time+ 10 sec extra
? Hint Small clue
A \(a_n=n^2+1\)
B \(a_n=2n\)
C \(a_n=n^2+n+1\)
D (a_n=n(n+1))
Explanation opens after your attempt
Correct Answer
D. (a_n=n(n+1))
Step 1
Concept
(n(n+1)) gives (2,6,12,20). In exams, check rules involving the product of consecutive numbers.
Step 2
Why this answer is correct
The correct answer is D. (a_n=n(n+1)). (n(n+1)) gives (2,6,12,20). In exams, check rules involving the product of consecutive numbers.
Step 3
Exam Tip
(n(n+1)) से (2,6,12,20) मिलते हैं। परीक्षा में लगातार दो संख्याओं के गुणन वाले नियम को जाँचें।
Login to save your score, XP, coins and progress. Login
यदि (a_n=n(n+1)) है, तो \(a_7\) का मान क्या होगा?
If (a_n=n(n+1)), what is the value of \(a_7\)?
#sequences
#progressions
#explicit-rule
#class-9
#medium
50 50-50 2 wrong hide
⏭ Skip Next question
+10 Time+ 10 sec extra
? Hint Small clue
A (56)
B (49)
C (42)
D (64)
Explanation opens after your attempt
Step 1
Concept
\(a_7=7\times8=56\). In exams, keep both (n) and (n+1) correct.
Step 2
Why this answer is correct
The correct answer is A. (56). \(a_7=7\times8=56\). In exams, keep both (n) and (n+1) correct.
Step 3
Exam Tip
\(a_7=7\times8=56\) है। परीक्षा में (n) और (n+1) दोनों को सही रखें।
Login to save your score, XP, coins and progress. Login
अनुक्रम \(2,4,7,11,\ldots\) का सामान्य पद क्या है?
What is the general term of the sequence \(2,4,7,11,\ldots\)?
#sequences
#progressions
#explicit-rule
#class-9
#medium
50 50-50 2 wrong hide
⏭ Skip Next question
+10 Time+ 10 sec extra
? Hint Small clue
A (a_n=\frac{n(n-1)}{2})
B \(a_n=n^2+1\)
C (a_n=\frac{n(n+1)}{2}+1)
D \(a_n=2n\)
Explanation opens after your attempt
Correct Answer
C. (a_n=\frac{n(n+1)}{2}+1)
Step 1
Concept
Adding (1) to triangular numbers gives (2,4,7,11). In exams, think of triangular numbers when differences are (2,3,4).
Step 2
Why this answer is correct
The correct answer is C. (a_n=\frac{n(n+1)}{2}+1). Adding (1) to triangular numbers gives (2,4,7,11). In exams, think of triangular numbers when differences are (2,3,4).
Step 3
Exam Tip
त्रिभुज संख्या में (1) जोड़ने से (2,4,7,11) मिलते हैं। परीक्षा में अंतर (2,3,4) दिखे तो त्रिभुज संख्या सोचें।
Login to save your score, XP, coins and progress. Login
यदि (a_n=\frac{n(n+1)}{2}+1) है, तो \(a_5\) का मान क्या होगा?
If (a_n=\frac{n(n+1)}{2}+1), what is the value of \(a_5\)?
#sequences
#progressions
#explicit-rule
#class-9
#medium
50 50-50 2 wrong hide
⏭ Skip Next question
+10 Time+ 10 sec extra
? Hint Small clue
A (15)
B (16)
C (17)
D (18)
Explanation opens after your attempt
Step 1
Concept
\(a_5=\frac{5\times6}{2}+1=16\). In exams, simplify the fractional part and add (1) at the end.
Step 2
Why this answer is correct
The correct answer is B. (16). \(a_5=\frac{5\times6}{2}+1=16\). In exams, simplify the fractional part and add (1) at the end.
Step 3
Exam Tip
\(a_5=\frac{5\times6}{2}+1=16\) है। परीक्षा में भिन्न भाग सरल करके अंत में (1) जोड़ें।
Login to save your score, XP, coins and progress. Login
अनुक्रम \(0,3,8,15,\ldots\) का सामान्य पद क्या है?
What is the general term of the sequence \(0,3,8,15,\ldots\)?
#sequences
#progressions
#explicit-rule
#class-9
#medium
50 50-50 2 wrong hide
⏭ Skip Next question
+10 Time+ 10 sec extra
? Hint Small clue
A \(a_n=n^2-1\)
B \(a_n=n^2+1\)
C \(a_n=2n-2\)
D (a_n=n(n+1))
Explanation opens after your attempt
Correct Answer
A. \(a_n=n^2-1\)
Step 1
Concept
\(n^2-1\) gives (0,3,8,15). In exams, match by subtracting (1) from square numbers.
Step 2
Why this answer is correct
The correct answer is A. \(a_n=n^2-1\). \(n^2-1\) gives (0,3,8,15). In exams, match by subtracting (1) from square numbers.
Step 3
Exam Tip
\(n^2-1\) से (0,3,8,15) मिलते हैं। परीक्षा में वर्ग संख्याओं से (1) घटाकर मिलान करें।
Login to save your score, XP, coins and progress. Login
यदि \(a_n=n^2-1\) है, तो कौन-सा पद (35) के बराबर होगा?
If \(a_n=n^2-1\), which term will be equal to (35)?
#sequences
#progressions
#explicit-rule
#class-9
#medium
50 50-50 2 wrong hide
⏭ Skip Next question
+10 Time+ 10 sec extra
? Hint Small clue
A (n=4)
B (n=5)
C (n=7)
D (n=6)
Explanation opens after your attempt
Step 1
Concept
From \(n^2-1=35\), we get \(n^2=36\) and (n=6). In exams, complete the square value to find the term number.
Step 2
Why this answer is correct
The correct answer is D. (n=6). From \(n^2-1=35\), we get \(n^2=36\) and (n=6). In exams, complete the square value to find the term number.
Step 3
Exam Tip
\(n^2-1=35\) से \(n^2=36\) और (n=6) मिलता है। परीक्षा में वर्ग पूरा करके पद संख्या निकालें।
Login to save your score, XP, coins and progress. Login
अनुक्रम \(3,5,9,17,\ldots\) के लिए सही स्पष्ट नियम कौन-सा है?
Which explicit rule is correct for the sequence \(3,5,9,17,\ldots\)?
#sequences
#progressions
#explicit-rule
#class-9
#medium
50 50-50 2 wrong hide
⏭ Skip Next question
+10 Time+ 10 sec extra
? Hint Small clue
A \(a_n=2n+1\)
B \(a_n=2^n-1\)
C \(a_n=2^n+1\)
D \(a_n=n^2+2\)
Explanation opens after your attempt
Correct Answer
C. \(a_n=2^n+1\)
Step 1
Concept
\(2^n+1\) gives (3,5,9,17). In exams, also check constant addition in power-based options.
Step 2
Why this answer is correct
The correct answer is C. \(a_n=2^n+1\). \(2^n+1\) gives (3,5,9,17). In exams, also check constant addition in power-based options.
Step 3
Exam Tip
\(2^n+1\) से (3,5,9,17) मिलते हैं। परीक्षा में घात वाले विकल्पों में स्थिर जोड़ भी जाँचें।
Login to save your score, XP, coins and progress. Login
यदि \(a_n=2^n+1\) है, तो \(a_5\) का मान क्या होगा?
If \(a_n=2^n+1\), what is the value of \(a_5\)?
#sequences
#progressions
#explicit-rule
#class-9
#medium
50 50-50 2 wrong hide
⏭ Skip Next question
+10 Time+ 10 sec extra
? Hint Small clue
A (33)
B (31)
C (32)
D (34)
Explanation opens after your attempt
Step 1
Concept
\(a_5=2^5+1=33\). In exams, find the power first and then add (1).
Step 2
Why this answer is correct
The correct answer is A. (33). \(a_5=2^5+1=33\). In exams, find the power first and then add (1).
Step 3
Exam Tip
\(a_5=2^5+1=33\) है। परीक्षा में पहले घात निकालें और फिर (1) जोड़ें।
Login to save your score, XP, coins and progress. Login
अनुक्रम \(5,11,29,83,\ldots\) का सामान्य पद क्या है?
What is the general term of the sequence \(5,11,29,83,\ldots\)?
#sequences
#progressions
#explicit-rule
#class-9
#medium
50 50-50 2 wrong hide
⏭ Skip Next question
+10 Time+ 10 sec extra
? Hint Small clue
A \(a_n=3n+2\)
B \(a_n=3^n+2\)
C \(a_n=3^n-2\)
D \(a_n=n^3+4\)
Explanation opens after your attempt
Correct Answer
B. \(a_n=3^n+2\)
Step 1
Concept
\(3^n+2\) gives (5,11,29,83). In exams, check powers in rapidly increasing sequences.
Step 2
Why this answer is correct
The correct answer is B. \(a_n=3^n+2\). \(3^n+2\) gives (5,11,29,83). In exams, check powers in rapidly increasing sequences.
Step 3
Exam Tip
\(3^n+2\) से (5,11,29,83) मिलते हैं। परीक्षा में तेज वृद्धि वाले अनुक्रमों में घात जाँचें।
Login to save your score, XP, coins and progress. Login
यदि \(a_n=3^n+2\) है, तो \(a_3\) का मान क्या होगा?
If \(a_n=3^n+2\), what is the value of \(a_3\)?
#sequences
#progressions
#explicit-rule
#class-9
#medium
50 50-50 2 wrong hide
⏭ Skip Next question
+10 Time+ 10 sec extra
? Hint Small clue
A (25)
B (27)
C (28)
D (29)
Explanation opens after your attempt
Step 1
Concept
\(a_3=3^3+2=29\). In exams, add the constant after finding the power.
Step 2
Why this answer is correct
The correct answer is D. (29). \(a_3=3^3+2=29\). In exams, add the constant after finding the power.
Step 3
Exam Tip
\(a_3=3^3+2=29\) है। परीक्षा में घात के बाद स्थिर संख्या जोड़ें।
Login to save your score, XP, coins and progress. Login
अनुक्रम \(6,18,54,162,\ldots\) के लिए सही सामान्य पद कौन-सा है?
Which general term is correct for the sequence \(6,18,54,162,\ldots\)?
#sequences
#progressions
#explicit-rule
#class-9
#medium
50 50-50 2 wrong hide
⏭ Skip Next question
+10 Time+ 10 sec extra
? Hint Small clue
A \(a_n=6n\)
B \(a_n=3^n+3\)
C \(a_n=2\cdot3^n\)
D \(a_n=6\cdot2^{n-1}\)
Explanation opens after your attempt
Correct Answer
C. \(a_n=2\cdot3^n\)
Step 1
Concept
\(2\cdot3^n\) gives (6,18,54,162). In exams, check powers of the base for geometric growth.
Step 2
Why this answer is correct
The correct answer is C. \(a_n=2\cdot3^n\). \(2\cdot3^n\) gives (6,18,54,162). In exams, check powers of the base for geometric growth.
Step 3
Exam Tip
\(2\cdot3^n\) से (6,18,54,162) मिलते हैं। परीक्षा में गुणोत्तर वृद्धि के लिए आधार की घात जाँचें।
Login to save your score, XP, coins and progress. Login
यदि \(a_n=5\cdot2^{n-1}\) है, तो \(a_5\) का मान क्या होगा?
If \(a_n=5\cdot2^{n-1}\), what is the value of \(a_5\)?
#sequences
#progressions
#explicit-rule
#class-9
#medium
50 50-50 2 wrong hide
⏭ Skip Next question
+10 Time+ 10 sec extra
? Hint Small clue
A (40)
B (80)
C (100)
D (160)
Explanation opens after your attempt
Step 1
Concept
\(a_5=5\cdot2^4=80\). In exams, apply the exponent (n-1) carefully.
Step 2
Why this answer is correct
The correct answer is B. (80). \(a_5=5\cdot2^4=80\). In exams, apply the exponent (n-1) carefully.
Step 3
Exam Tip
\(a_5=5\cdot2^4=80\) है। परीक्षा में (n-1) वाला घातांक ध्यान से लगाएँ।
Login to save your score, XP, coins and progress. Login
अनुक्रम \(5,10,20,40,\ldots\) का सामान्य पद क्या है?
What is the general term of the sequence \(5,10,20,40,\ldots\)?
#sequences
#progressions
#explicit-rule
#class-9
#medium
50 50-50 2 wrong hide
⏭ Skip Next question
+10 Time+ 10 sec extra
? Hint Small clue
A \(a_n=5\cdot2^{n-1}\)
B \(a_n=5n\)
C \(a_n=2^n+3\)
D \(a_n=10n-5\)
Explanation opens after your attempt
Correct Answer
A. \(a_n=5\cdot2^{n-1}\)
Step 1
Concept
The first term is (5), and each term is multiplied by (2). In exams, check both the first term and ratio in a geometric sequence.
Step 2
Why this answer is correct
The correct answer is A. \(a_n=5\cdot2^{n-1}\). The first term is (5), and each term is multiplied by (2). In exams, check both the first term and ratio in a geometric sequence.
Step 3
Exam Tip
पहला पद (5) है और हर बार (2) से गुणा हो रहा है। परीक्षा में गुणोत्तर अनुक्रम में पहले पद और अनुपात दोनों देखें।
Login to save your score, XP, coins and progress. Login
यदि \(a_n=2n^2+3\) है, तो \(a_4\) का मान क्या होगा?
If \(a_n=2n^2+3\), what is the value of \(a_4\)?
#sequences
#progressions
#explicit-rule
#class-9
#medium
50 50-50 2 wrong hide
⏭ Skip Next question
+10 Time+ 10 sec extra
? Hint Small clue
A (29)
B (31)
C (33)
D (35)
Explanation opens after your attempt
Step 1
Concept
\(a_4=2\times16+3=35\). In exams, square first and multiply by (2).
Step 2
Why this answer is correct
The correct answer is D. (35). \(a_4=2\times16+3=35\). In exams, square first and multiply by (2).
Step 3
Exam Tip
\(a_4=2\times16+3=35\) है। परीक्षा में वर्ग निकालकर (2) से गुणा करें।
Login to save your score, XP, coins and progress. Login
अनुक्रम \(5,11,21,35,\ldots\) के लिए सही स्पष्ट नियम कौन-सा है?
Which explicit rule is correct for the sequence \(5,11,21,35,\ldots\)?
#sequences
#progressions
#explicit-rule
#class-9
#medium
50 50-50 2 wrong hide
⏭ Skip Next question
+10 Time+ 10 sec extra
? Hint Small clue
A \(a_n=5n\)
B \(a_n=n^2+4\)
C \(a_n=2n^2+3\)
D \(a_n=3n^2+2\)
Explanation opens after your attempt
Correct Answer
C. \(a_n=2n^2+3\)
Step 1
Concept
\(2n^2+3\) gives (5,11,21,35). In exams, test options by putting (n=1,2,3).
Step 2
Why this answer is correct
The correct answer is C. \(a_n=2n^2+3\). \(2n^2+3\) gives (5,11,21,35). In exams, test options by putting (n=1,2,3).
Step 3
Exam Tip
\(2n^2+3\) से (5,11,21,35) मिलते हैं। परीक्षा में (n=1,2,3) रखकर विकल्प जाँचें।
Login to save your score, XP, coins and progress. Login
यदि \(a_n=3n^2-n\) है, तो \(a_5\) का मान क्या होगा?
If \(a_n=3n^2-n\), what is the value of \(a_5\)?
#sequences
#progressions
#explicit-rule
#class-9
#medium
50 50-50 2 wrong hide
⏭ Skip Next question
+10 Time+ 10 sec extra
? Hint Small clue
A (70)
B (72)
C (74)
D (76)
Explanation opens after your attempt
Step 1
Concept
\(a_5=3\times25-5=70\). In exams, subtract (n) from the square-based part.
Step 2
Why this answer is correct
The correct answer is A. (70). \(a_5=3\times25-5=70\). In exams, subtract (n) from the square-based part.
Step 3
Exam Tip
\(a_5=3\times25-5=70\) है। परीक्षा में वर्ग वाले भाग से (n) घटाएँ।
Login to save your score, XP, coins and progress. Login
अनुक्रम \(2,10,24,44,\ldots\) का सामान्य पद क्या है?
What is the general term of the sequence \(2,10,24,44,\ldots\)?
#sequences
#progressions
#explicit-rule
#class-9
#medium
50 50-50 2 wrong hide
⏭ Skip Next question
+10 Time+ 10 sec extra
? Hint Small clue
A \(a_n=2n^2\)
B \(a_n=3n^2-n\)
C \(a_n=n^2+n\)
D \(a_n=4n^2-2n\)
Explanation opens after your attempt
Correct Answer
B. \(a_n=3n^2-n\)
Step 1
Concept
\(3n^2-n\) gives (2,10,24,44). In exams, match polynomial rules using small (n) values.
Step 2
Why this answer is correct
The correct answer is B. \(a_n=3n^2-n\). \(3n^2-n\) gives (2,10,24,44). In exams, match polynomial rules using small (n) values.
Step 3
Exam Tip
\(3n^2-n\) से (2,10,24,44) मिलते हैं। परीक्षा में बहुपद नियमों को छोटे (n) मानों से मिलाएँ।
Login to save your score, XP, coins and progress. Login
यदि \(a_n=n^3+n\) है, तो \(a_3\) का मान क्या होगा?
If \(a_n=n^3+n\), what is the value of \(a_3\)?
#sequences
#progressions
#explicit-rule
#class-9
#medium
50 50-50 2 wrong hide
⏭ Skip Next question
+10 Time+ 10 sec extra
? Hint Small clue
A (24)
B (27)
C (30)
D (33)
Explanation opens after your attempt
Step 1
Concept
\(a_3=27+3=30\). In exams, add both the cube and (n).
Step 2
Why this answer is correct
The correct answer is C. (30). \(a_3=27+3=30\). In exams, add both the cube and (n).
Step 3
Exam Tip
\(a_3=27+3=30\) है। परीक्षा में घन और (n) दोनों जोड़ें।
Login to save your score, XP, coins and progress. Login
अनुक्रम \(2,10,30,68,\ldots\) के लिए सही सामान्य पद कौन-सा है?
Which general term is correct for the sequence \(2,10,30,68,\ldots\)?
#sequences
#progressions
#explicit-rule
#class-9
#medium
50 50-50 2 wrong hide
⏭ Skip Next question
+10 Time+ 10 sec extra
? Hint Small clue
A \(a_n=n^3+n\)
B \(a_n=n^2+n\)
C \(a_n=2n^3\)
D \(a_n=n^3+1\)
Explanation opens after your attempt
Correct Answer
A. \(a_n=n^3+n\)
Step 1
Concept
\(n^3+n\) gives (2,10,30,68). In exams, test the cube-based rule on the first three terms.
Step 2
Why this answer is correct
The correct answer is A. \(a_n=n^3+n\). \(n^3+n\) gives (2,10,30,68). In exams, test the cube-based rule on the first three terms.
Step 3
Exam Tip
\(n^3+n\) से (2,10,30,68) मिलते हैं। परीक्षा में घन वाले नियम को पहले तीन पदों पर जाँचें।
Login to save your score, XP, coins and progress. Login
यदि \(a_n=2n-1\) है, तो कौन-सा पद (41) के बराबर होगा?
If \(a_n=2n-1\), which term will be equal to (41)?
#sequences
#progressions
#explicit-rule
#class-9
#medium
50 50-50 2 wrong hide
⏭ Skip Next question
+10 Time+ 10 sec extra
? Hint Small clue
A (n=18)
B (n=19)
C (n=20)
D (n=21)
Explanation opens after your attempt
Step 1
Concept
From (2n-1=41), we get (n=21). In exams, find the term number of an odd number using the formula.
Step 2
Why this answer is correct
The correct answer is D. (n=21). From (2n-1=41), we get (n=21). In exams, find the term number of an odd number using the formula.
Step 3
Exam Tip
(2n-1=41) से (n=21) मिलता है। परीक्षा में विषम संख्या के पद को सूत्र से निकालें।
Login to save your score, XP, coins and progress. Login
अनुक्रम \(7,10,13,16,\ldots\) में (58) कौन-सा पद है?
In the sequence \(7,10,13,16,\ldots\), which term is (58)?
#sequences
#progressions
#explicit-rule
#class-9
#medium
50 50-50 2 wrong hide
⏭ Skip Next question
+10 Time+ 10 sec extra
? Hint Small clue
A सत्रहवाँ पद / (17)th term
B अठारहवाँ पद / (18)th term
C उन्नीसवाँ पद / (19)th term
D बीसवाँ पद / (20)th term
Explanation opens after your attempt
Correct Answer
B. अठारहवाँ पद / (18)th term
Step 1
Concept
Its rule is \(a_n=3n+4\), and (3n+4=58) gives (n=18). In exams, write the rule first and compare it with the given term.
Step 2
Why this answer is correct
The correct answer is B. अठारहवाँ पद / (18)th term. Its rule is \(a_n=3n+4\), and (3n+4=58) gives (n=18). In exams, write the rule first and compare it with the given term.
Step 3
Exam Tip
इसका नियम \(a_n=3n+4\) है और (3n+4=58) से (n=18) है। परीक्षा में पहले नियम लिखकर दिए पद से तुलना करें।
Login to save your score, XP, coins and progress. Login
अनुक्रम \(8,14,20,26,\ldots\) का सामान्य पद क्या है?
What is the general term of the sequence \(8,14,20,26,\ldots\)?
#sequences
#progressions
#explicit-rule
#class-9
#medium
50 50-50 2 wrong hide
⏭ Skip Next question
+10 Time+ 10 sec extra
? Hint Small clue
A \(a_n=8n\)
B \(a_n=6n-2\)
C \(a_n=6n+2\)
D \(a_n=2n+6\)
Explanation opens after your attempt
Correct Answer
C. \(a_n=6n+2\)
Step 1
Concept
The difference is (6) and the first term is (8), so \(a_n=6n+2\). In exams, find the constant to match the first term.
Step 2
Why this answer is correct
The correct answer is C. \(a_n=6n+2\). The difference is (6) and the first term is (8), so \(a_n=6n+2\). In exams, find the constant to match the first term.
Step 3
Exam Tip
अंतर (6) है और पहला पद (8) है, इसलिए \(a_n=6n+2\) है। परीक्षा में पहला पद मिलाने के लिए स्थिर संख्या निकालें।
Login to save your score, XP, coins and progress. Login
यदि \(a_n=6n+2\) है, तो पहले तीन पदों का योग क्या होगा?
If \(a_n=6n+2\), what is the sum of the first three terms?
#sequences
#progressions
#explicit-rule
#class-9
#medium
50 50-50 2 wrong hide
⏭ Skip Next question
+10 Time+ 10 sec extra
? Hint Small clue
A (42)
B (40)
C (44)
D (46)
Explanation opens after your attempt
Step 1
Concept
The first three terms are (8,14,20), and their sum is (42). In exams, find all required terms when a sum is asked.
Step 2
Why this answer is correct
The correct answer is A. (42). The first three terms are (8,14,20), and their sum is (42). In exams, find all required terms when a sum is asked.
Step 3
Exam Tip
पहले तीन पद (8,14,20) हैं और योग (42) है। परीक्षा में योग पूछे जाने पर सभी आवश्यक पद निकालें।
Login to save your score, XP, coins and progress. Login
यदि \(a_n=4n-1\) है, तो \(a_7-a_3\) का मान क्या होगा?
If \(a_n=4n-1\), what is the value of \(a_7-a_3\)?
#sequences
#progressions
#explicit-rule
#class-9
#medium
50 50-50 2 wrong hide
⏭ Skip Next question
+10 Time+ 10 sec extra
? Hint Small clue
A (12)
B (14)
C (15)
D (16)
Explanation opens after your attempt
Step 1
Concept
\(a_7=27\) and \(a_3=11\), so the difference is (16). In exams, find both terms separately.
Step 2
Why this answer is correct
The correct answer is D. (16). \(a_7=27\) and \(a_3=11\), so the difference is (16). In exams, find both terms separately.
Step 3
Exam Tip
\(a_7=27\) और \(a_3=11\), इसलिए अंतर (16) है। परीक्षा में दोनों पद अलग-अलग निकालें।
Login to save your score, XP, coins and progress. Login
यदि \(a_n=n^2+5n\) है, तो \(a_4:a_2\) का अनुपात क्या होगा?
If \(a_n=n^2+5n\), what is the ratio \(a_4:a_2\)?
#sequences
#progressions
#explicit-rule
#class-9
#medium
50 50-50 2 wrong hide
⏭ Skip Next question
+10 Time+ 10 sec extra
? Hint Small clue
A (9:4)
B (18:7)
C (7:18)
D (36:7)
Explanation opens after your attempt
Step 1
Concept
\(a_4=36\) and \(a_2=14\), so the ratio is (18:7). In exams, do not forget to simplify the ratio.
Step 2
Why this answer is correct
The correct answer is B. (18:7). \(a_4=36\) and \(a_2=14\), so the ratio is (18:7). In exams, do not forget to simplify the ratio.
Step 3
Exam Tip
\(a_4=36\) और \(a_2=14\), इसलिए अनुपात (18:7) है। परीक्षा में अनुपात को सरल करना न भूलें।
Login to save your score, XP, coins and progress. Login
यदि \(a_n=2n^2-n+1\) है, तो कौन-सा कथन सही है?
If \(a_n=2n^2-n+1\), which statement is correct?
#sequences
#progressions
#explicit-rule
#class-9
#medium
50 50-50 2 wrong hide
⏭ Skip Next question
+10 Time+ 10 sec extra
? Hint Small clue
A \(a_2=7\) और \(a_3=16\) / \(a_2=7\) and \(a_3=16\)
B \(a_2=6\) और \(a_3=15\) / \(a_2=6\) and \(a_3=15\)
C \(a_2=8\) और \(a_3=17\) / \(a_2=8\) and \(a_3=17\)
D \(a_2=7\) और \(a_3=18\) / \(a_2=7\) and \(a_3=18\)
Explanation opens after your attempt
Correct Answer
A. \(a_2=7\) और \(a_3=16\) / \(a_2=7\) and \(a_3=16\)
Step 1
Concept
\(a_2=8-2+1=7\) and \(a_3=18-3+1=16\). In exams, use a separate value of (n) for each term.
Step 2
Why this answer is correct
The correct answer is A. \(a_2=7\) और \(a_3=16\) / \(a_2=7\) and \(a_3=16\). \(a_2=8-2+1=7\) and \(a_3=18-3+1=16\). In exams, use a separate value of (n) for each term.
Step 3
Exam Tip
\(a_2=8-2+1=7\) और \(a_3=18-3+1=16\) है। परीक्षा में प्रत्येक पद के लिए (n) का अलग मान रखें।
Login to save your score, XP, coins and progress. Login
अनुक्रम \(1,5,11,19,\ldots\) का सामान्य पद क्या है?
What is the general term of the sequence \(1,5,11,19,\ldots\)?
#sequences
#progressions
#explicit-rule
#class-9
#medium
50 50-50 2 wrong hide
⏭ Skip Next question
+10 Time+ 10 sec extra
? Hint Small clue
A \(a_n=n^2+1\)
B \(a_n=2n^2-1\)
C \(a_n=n^2+n-1\)
D \(a_n=n^2+2n\)
Explanation opens after your attempt
Correct Answer
C. \(a_n=n^2+n-1\)
Step 1
Concept
\(n^2+n-1\) gives (1,5,11,19). In exams, check a quadratic rule when second differences are constant.
Step 2
Why this answer is correct
The correct answer is C. \(a_n=n^2+n-1\). \(n^2+n-1\) gives (1,5,11,19). In exams, check a quadratic rule when second differences are constant.
Step 3
Exam Tip
\(n^2+n-1\) से (1,5,11,19) मिलते हैं। परीक्षा में दूसरे अंतर समान हों तो वर्गीय नियम जाँचें।
Login to save your score, XP, coins and progress. Login
यदि \(a_n=n^2+n-1\) है, तो \(a_6\) का मान क्या होगा?
If \(a_n=n^2+n-1\), what is the value of \(a_6\)?
#sequences
#progressions
#explicit-rule
#class-9
#medium
50 50-50 2 wrong hide
⏭ Skip Next question
+10 Time+ 10 sec extra
? Hint Small clue
A (37)
B (39)
C (40)
D (41)
Explanation opens after your attempt
Step 1
Concept
\(a_6=36+6-1=41\). In exams, add the square and (n), then subtract (1).
Step 2
Why this answer is correct
The correct answer is D. (41). \(a_6=36+6-1=41\). In exams, add the square and (n), then subtract (1).
Step 3
Exam Tip
\(a_6=36+6-1=41\) है। परीक्षा में वर्ग और (n) जोड़कर (1) घटाएँ।
Login to save your score, XP, coins and progress. Login
यदि \(a_n=100-7n\) है, तो \(a_8\) का मान क्या होगा?
If \(a_n=100-7n\), what is the value of \(a_8\)?
#sequences
#progressions
#explicit-rule
#class-9
#medium
50 50-50 2 wrong hide
⏭ Skip Next question
+10 Time+ 10 sec extra
? Hint Small clue
A (42)
B (44)
C (46)
D (48)
Explanation opens after your attempt
Step 1
Concept
\(a_8=100-56=44\). In exams, multiply first in a decreasing formula.
Step 2
Why this answer is correct
The correct answer is B. (44). \(a_8=100-56=44\). In exams, multiply first in a decreasing formula.
Step 3
Exam Tip
\(a_8=100-56=44\) है। परीक्षा में घटते सूत्र में गुणन पहले करें।
Login to save your score, XP, coins and progress. Login
अनुक्रम \(93,86,79,72,\ldots\) के लिए सही स्पष्ट नियम कौन-सा है?
Which explicit rule is correct for the sequence \(93,86,79,72,\ldots\)?
#sequences
#progressions
#explicit-rule
#class-9
#medium
50 50-50 2 wrong hide
⏭ Skip Next question
+10 Time+ 10 sec extra
? Hint Small clue
A \(a_n=100-7n\)
B \(a_n=93-7n\)
C \(a_n=7n+86\)
D \(a_n=100+n\)
Explanation opens after your attempt
Correct Answer
A. \(a_n=100-7n\)
Step 1
Concept
At (n=1) it gives (93), and at (n=2) it gives (86), so \(a_n=100-7n\). In exams, match the first term of a decreasing sequence.
Step 2
Why this answer is correct
The correct answer is A. \(a_n=100-7n\). At (n=1) it gives (93), and at (n=2) it gives (86), so \(a_n=100-7n\). In exams, match the first term of a decreasing sequence.
Step 3
Exam Tip
(n=1) पर (93) और (n=2) पर (86) मिलता है, इसलिए \(a_n=100-7n\) है। परीक्षा में घटते अनुक्रम का पहला पद मिलाएँ।
Login to save your score, XP, coins and progress. Login
यदि \(a_n=\frac{3n+1}{2}\) है, तो \(a_5\) का मान क्या होगा?
If \(a_n=\frac{3n+1}{2}\), what is the value of \(a_5\)?
#sequences
#progressions
#explicit-rule
#class-9
#medium
50 50-50 2 wrong hide
⏭ Skip Next question
+10 Time+ 10 sec extra
? Hint Small clue
A (6)
B (7)
C (8)
D (9)
Explanation opens after your attempt
Step 1
Concept
\(a_5=\frac{16}{2}=8\). In exams, simplify the numerator first and then divide.
Step 2
Why this answer is correct
The correct answer is C. (8). \(a_5=\frac{16}{2}=8\). In exams, simplify the numerator first and then divide.
Step 3
Exam Tip
\(a_5=\frac{16}{2}=8\) है। परीक्षा में पहले अंश को सरल करें और फिर भाग दें।
Login to save your score, XP, coins and progress. Login
अनुक्रम \(2,\frac{7}{2},5,\frac{13}{2},\ldots\) का सामान्य पद क्या है?
What is the general term of the sequence \(2,\frac{7}{2},5,\frac{13}{2},\ldots\)?
#sequences
#progressions
#explicit-rule
#class-9
#medium
50 50-50 2 wrong hide
⏭ Skip Next question
+10 Time+ 10 sec extra
? Hint Small clue
A \(a_n=\frac{n+3}{2}\)
B \(a_n=\frac{3n+1}{2}\)
C \(a_n=\frac{2n+3}{2}\)
D \(a_n=2n\)
Explanation opens after your attempt
Correct Answer
B. \(a_n=\frac{3n+1}{2}\)
Step 1
Concept
\(\frac{3n+1}{2}\) gives \(2,\frac{7}{2},5,\frac{13}{2}\). In exams, match fractional terms using small (n) values.
Step 2
Why this answer is correct
The correct answer is B. \(a_n=\frac{3n+1}{2}\). \(\frac{3n+1}{2}\) gives \(2,\frac{7}{2},5,\frac{13}{2}\). In exams, match fractional terms using small (n) values.
Step 3
Exam Tip
\(\frac{3n+1}{2}\) से \(2,\frac{7}{2},5,\frac{13}{2}\) मिलते हैं। परीक्षा में भिन्न पदों को छोटे (n) मानों से मिलाएँ।
Login to save your score, XP, coins and progress. Login
यदि (a_n=\frac{n(n+1)}{2}) है, तो \(a_6\) का मान क्या होगा?
If (a_n=\frac{n(n+1)}{2}), what is the value of \(a_6\)?
#sequences
#progressions
#explicit-rule
#class-9
#medium
50 50-50 2 wrong hide
⏭ Skip Next question
+10 Time+ 10 sec extra
? Hint Small clue
A (21)
B (18)
C (24)
D (27)
Explanation opens after your attempt
Step 1
Concept
\(a_6=\frac{6\times7}{2}=21\). In exams, multiply first and then divide by (2).
Step 2
Why this answer is correct
The correct answer is A. (21). \(a_6=\frac{6\times7}{2}=21\). In exams, multiply first and then divide by (2).
Step 3
Exam Tip
\(a_6=\frac{6\times7}{2}=21\) है। परीक्षा में गुणन के बाद (2) से भाग दें।
Login to save your score, XP, coins and progress. Login
यदि (a_n=\frac{n(n+1)}{2}) है, तो कौन-सा पद (28) के बराबर होगा?
If (a_n=\frac{n(n+1)}{2}), which term will be equal to (28)?
#sequences
#progressions
#explicit-rule
#class-9
#medium
50 50-50 2 wrong hide
⏭ Skip Next question
+10 Time+ 10 sec extra
? Hint Small clue
A (n=5)
B (n=6)
C (n=8)
D (n=7)
Explanation opens after your attempt
Step 1
Concept
\(\frac{7\times8}{2}=28\), so (n=7). In exams, remembering triangular numbers is useful.
Step 2
Why this answer is correct
The correct answer is D. (n=7). \(\frac{7\times8}{2}=28\), so (n=7). In exams, remembering triangular numbers is useful.
Step 3
Exam Tip
\(\frac{7\times8}{2}=28\), इसलिए (n=7) है। परीक्षा में त्रिभुज संख्याओं को याद रखना उपयोगी है।
Login to save your score, XP, coins and progress. Login
यदि \(a_n=2^n+n\) है, तो \(a_4\) का मान क्या होगा?
If \(a_n=2^n+n\), what is the value of \(a_4\)?
#sequences
#progressions
#explicit-rule
#class-9
#medium
50 50-50 2 wrong hide
⏭ Skip Next question
+10 Time+ 10 sec extra
? Hint Small clue
A (16)
B (18)
C (20)
D (22)
Explanation opens after your attempt
Step 1
Concept
\(a_4=2^4+4=20\). In exams, add both the power and (n).
Step 2
Why this answer is correct
The correct answer is C. (20). \(a_4=2^4+4=20\). In exams, add both the power and (n).
Step 3
Exam Tip
\(a_4=2^4+4=20\) है। परीक्षा में घात और (n) दोनों जोड़ें।
Login to save your score, XP, coins and progress. Login
अनुक्रम \(3,6,11,20,\ldots\) का सामान्य पद क्या है?
What is the general term of the sequence \(3,6,11,20,\ldots\)?
#sequences
#progressions
#explicit-rule
#class-9
#medium
50 50-50 2 wrong hide
⏭ Skip Next question
+10 Time+ 10 sec extra
? Hint Small clue
A \(a_n=2^n+n\)
B \(a_n=2n+1\)
C \(a_n=n^2+2\)
D \(a_n=3n\)
Explanation opens after your attempt
Correct Answer
A. \(a_n=2^n+n\)
Step 1
Concept
\(2^n+n\) gives (3,6,11,20). In exams, also check the extra (n) in power-based rules.
Step 2
Why this answer is correct
The correct answer is A. \(a_n=2^n+n\). \(2^n+n\) gives (3,6,11,20). In exams, also check the extra (n) in power-based rules.
Step 3
Exam Tip
\(2^n+n\) से (3,6,11,20) मिलते हैं। परीक्षा में घात वाले नियमों में अतिरिक्त (n) भी जाँचें।
Login to save your score, XP, coins and progress. Login
यदि \(a_n=3^n-n\) है, तो \(a_3\) का मान क्या होगा?
If \(a_n=3^n-n\), what is the value of \(a_3\)?
#sequences
#progressions
#explicit-rule
#class-9
#medium
50 50-50 2 wrong hide
⏭ Skip Next question
+10 Time+ 10 sec extra
? Hint Small clue
A (21)
B (24)
C (27)
D (30)
Explanation opens after your attempt
Step 1
Concept
\(a_3=27-3=24\). In exams, find the power and subtract the current (n).
Step 2
Why this answer is correct
The correct answer is B. (24). \(a_3=27-3=24\). In exams, find the power and subtract the current (n).
Step 3
Exam Tip
\(a_3=27-3=24\) है। परीक्षा में घात निकालकर वर्तमान (n) घटाएँ।
Login to save your score, XP, coins and progress. Login
अनुक्रम \(2,7,24,77,\ldots\) के लिए सही स्पष्ट नियम कौन-सा है?
Which explicit rule is correct for the sequence \(2,7,24,77,\ldots\)?
#sequences
#progressions
#explicit-rule
#class-9
#medium
50 50-50 2 wrong hide
⏭ Skip Next question
+10 Time+ 10 sec extra
? Hint Small clue
A \(a_n=3^n+1\)
B \(a_n=2^n+n\)
C \(a_n=3n-1\)
D \(a_n=3^n-n\)
Explanation opens after your attempt
Correct Answer
D. \(a_n=3^n-n\)
Step 1
Concept
\(3^n-n\) gives (2,7,24,77). In exams, also test options where the term number is subtracted from a power.
Step 2
Why this answer is correct
The correct answer is D. \(a_n=3^n-n\). \(3^n-n\) gives (2,7,24,77). In exams, also test options where the term number is subtracted from a power.
Step 3
Exam Tip
\(3^n-n\) से (2,7,24,77) मिलते हैं। परीक्षा में घात में से पद संख्या घटाकर भी विकल्प जाँचें।
Login to save your score, XP, coins and progress. Login
यदि \(a_n=2n^2+2n\) है, तो कौन-सा पद (60) के बराबर होगा?
If \(a_n=2n^2+2n\), which term will be equal to (60)?
#sequences
#progressions
#explicit-rule
#class-9
#medium
50 50-50 2 wrong hide
⏭ Skip Next question
+10 Time+ 10 sec extra
? Hint Small clue
A (n=4)
B (n=6)
C (n=5)
D (n=7)
Explanation opens after your attempt
Step 1
Concept
Putting (n=5) in \(2n^2+2n=60\) gives (60). In exams, you can also check quickly by substituting options.
Step 2
Why this answer is correct
The correct answer is C. (n=5). Putting (n=5) in \(2n^2+2n=60\) gives (60). In exams, you can also check quickly by substituting options.
Step 3
Exam Tip
\(2n^2+2n=60\) में (n=5) रखने पर मान (60) मिलता है। परीक्षा में विकल्पों को रखकर भी जल्दी जाँच सकते हैं।
Login to save your score, XP, coins and progress. Login
अनुक्रम \(4,12,24,40,\ldots\) का सामान्य पद क्या है?
What is the general term of the sequence \(4,12,24,40,\ldots\)?
#sequences
#progressions
#explicit-rule
#class-9
#medium
50 50-50 2 wrong hide
⏭ Skip Next question
+10 Time+ 10 sec extra
? Hint Small clue
A \(a_n=4n\)
B \(a_n=2n^2+2n\)
C \(a_n=n^2+3n\)
D \(a_n=2n^2\)
Explanation opens after your attempt
Correct Answer
B. \(a_n=2n^2+2n\)
Step 1
Concept
\(2n^2+2n\) gives (4,12,24,40). In exams, check a quadratic rule when second differences are constant.
Step 2
Why this answer is correct
The correct answer is B. \(a_n=2n^2+2n\). \(2n^2+2n\) gives (4,12,24,40). In exams, check a quadratic rule when second differences are constant.
Step 3
Exam Tip
\(2n^2+2n\) से (4,12,24,40) मिलते हैं। परीक्षा में दूसरे अंतर समान हों तो वर्गीय नियम जाँचें।
Login to save your score, XP, coins and progress. Login
यदि \(a_n=5n^2-4n\) है, तो \(a_4\) का मान क्या होगा?
If \(a_n=5n^2-4n\), what is the value of \(a_4\)?
#sequences
#progressions
#explicit-rule
#class-9
#medium
50 50-50 2 wrong hide
⏭ Skip Next question
+10 Time+ 10 sec extra
? Hint Small clue
A (64)
B (60)
C (68)
D (72)
Explanation opens after your attempt
Step 1
Concept
\(a_4=5\times16-16=64\). In exams, subtract the linear part from the square-based part.
Step 2
Why this answer is correct
The correct answer is A. (64). \(a_4=5\times16-16=64\). In exams, subtract the linear part from the square-based part.
Step 3
Exam Tip
\(a_4=5\times16-16=64\) है। परीक्षा में वर्ग वाले भाग से रैखिक भाग घटाएँ।
Login to save your score, XP, coins and progress. Login
