Class 9 Mathematics - Sequences and Progressions - nth term Expert Quiz

Level 58 • 50/50 questions • 25 seconds per question.

Level readiness 50/50 Questions
Time Left 20:50 25 sec/question
RewardsCoins + XP
ModeClassic Quiz
Share
Question 1 / 50 0 score
Answered 0/50 Correct 0 Time 20:50

श्रेणी \(17,25,33,41,\ldots\) का (n)वां पद क्या है?

What is the (n)th term of the sequence \(17,25,33,41,\ldots\)?

Explanation opens after your attempt
Correct Answer

C. (8n+9)

Step 1

Concept

The first term is (17) and the difference is (8), so (a_n=17+(n-1)8=8n+9). In an arithmetic sequence, (n-1) differences are added.

Step 2

Why this answer is correct

The correct answer is C. (8n+9). The first term is (17) and the difference is (8), so (a_n=17+(n-1)8=8n+9). In an arithmetic sequence, (n-1) differences are added.

Step 3

Exam Tip

पहला पद (17) और अंतर (8) है, इसलिए (a_n=17+(n-1)8=8n+9)। समान्तर श्रेणी में (n-1) अंतर जुड़ते हैं।

Open Question Page
Ask Friends

यदि \(a_n=7n^2-3n+5\), तो \(a_6\) का मान क्या होगा?

If \(a_n=7n^2-3n+5\), what is the value of \(a_6\)?

Explanation opens after your attempt
Correct Answer

A. (239)

Step 1

Concept

(a_6=7(6)2-3(6)+5=239). In a squared term, calculate \(n^2\) first.

Step 2

Why this answer is correct

The correct answer is A. (239). (a_6=7(6)2-3(6)+5=239). In a squared term, calculate \(n^2\) first.

Step 3

Exam Tip

(a_6=7(6)2-3(6)+5=239)। वर्ग वाले पद में पहले \(n^2\) निकालें।

Open Question Page
Ask Friends

किसी समान्तर श्रेणी में \(a_6=47\) और \(a_{13}=110\) है। उसका (n)वां पद क्या होगा?

In an arithmetic sequence, \(a_6=47\) and \(a_{13}=110\). What is its (n)th term?

Explanation opens after your attempt
Correct Answer

B. (9n-7)

Step 1

Concept

From (7d=63), (d=9) and \(a_1=2\), so \(a_n=9n-7\). From two given terms, find the common difference first.

Step 2

Why this answer is correct

The correct answer is B. (9n-7). From (7d=63), (d=9) and \(a_1=2\), so \(a_n=9n-7\). From two given terms, find the common difference first.

Step 3

Exam Tip

(7d=63) से (d=9) और \(a_1=2\), इसलिए \(a_n=9n-7\)। दो दिए पदों से पहले सामान्य अंतर निकालें।

Open Question Page
Ask Friends

श्रेणी \(9,26,51,84,125,\ldots\) का (n)वां पद कौन सा है?

Which is the (n)th term of the sequence \(9,26,51,84,125,\ldots\)?

Explanation opens after your attempt
Correct Answer

B. \(4n^2+5n\)

Step 1

Concept

The terms match \(4n^2+5n\). In a quadratic pattern, test the options on the first three terms.

Step 2

Why this answer is correct

The correct answer is B. \(4n^2+5n\). The terms match \(4n^2+5n\). In a quadratic pattern, test the options on the first three terms.

Step 3

Exam Tip

पद \(4n^2+5n\) से मिलते हैं। द्विघात पैटर्न में विकल्पों को पहले तीन पदों पर जांचें।

Open Question Page
Ask Friends

यदि \(a_n=11n-15\), तो \(a_{2r-1}\) किसके बराबर होगा?

If \(a_n=11n-15\), what is \(a_{2r-1}\)?

Explanation opens after your attempt
Correct Answer

A. (22r-26)

Step 1

Concept

Putting (n=2r-1), (a_{2r-1}=11(2r-1)-15=22r-26). Substitute the whole expression used as the index.

Step 2

Why this answer is correct

The correct answer is A. (22r-26). Putting (n=2r-1), (a_{2r-1}=11(2r-1)-15=22r-26). Substitute the whole expression used as the index.

Step 3

Exam Tip

(n=2r-1) रखने पर (a_{2r-1}=11(2r-1)-15=22r-26)। सूचकांक का पूरा व्यंजक प्रतिस्थापित करें।

Open Question Page
Ask Friends

श्रेणी \(6,30,150,750,\ldots\) का (6)वां पद क्या होगा?

What is the (6)th term of the sequence \(6,30,150,750,\ldots\)?

Explanation opens after your attempt
Correct Answer

A. (18750)

Step 1

Concept

This is a geometric sequence and \(a_6=6\cdot5^5=18750\). In a geometric sequence, the exponent is (n-1).

Step 2

Why this answer is correct

The correct answer is A. (18750). This is a geometric sequence and \(a_6=6\cdot5^5=18750\). In a geometric sequence, the exponent is (n-1).

Step 3

Exam Tip

यह गुणोत्तर श्रेणी है और \(a_6=6\cdot5^5=18750\)। गुणोत्तर श्रेणी में घात (n-1) होती है।

Open Question Page
Ask Friends

यदि \(a_n=2n^2+9n-11\), तो \(a_{10}-a_4\) का मान क्या है?

If \(a_n=2n^2+9n-11\), what is the value of \(a_{10}-a_4\)?

Explanation opens after your attempt
Correct Answer

B. (204)

Step 1

Concept

\(a_{10}=279\) and \(a_4=75\), so the difference is (204). Find both terms separately before subtracting.

Step 2

Why this answer is correct

The correct answer is B. (204). \(a_{10}=279\) and \(a_4=75\), so the difference is (204). Find both terms separately before subtracting.

Step 3

Exam Tip

\(a_{10}=279\) और \(a_4=75\), इसलिए अंतर (204) है। दोनों पद अलग निकालकर घटाएं।

Open Question Page
Ask Friends

श्रेणी \(5,17,37,65,101,\ldots\) का (n)वां पद क्या है?

What is the (n)th term of the sequence \(5,17,37,65,101,\ldots\)?

Explanation opens after your attempt
Correct Answer

A. \(4n^2+1\)

Step 1

Concept

The second differences are (8), and \(4n^2+1\) gives all starting terms. Half of the second difference is the coefficient of \(n^2\).

Step 2

Why this answer is correct

The correct answer is A. \(4n^2+1\). The second differences are (8), and \(4n^2+1\) gives all starting terms. Half of the second difference is the coefficient of \(n^2\).

Step 3

Exam Tip

दूसरे अंतर (8) हैं और \(4n^2+1\) सभी शुरुआती पद देता है। दूसरे अंतर का आधा \(n^2\) का गुणांक होता है।

Open Question Page
Ask Friends

यदि \(a_n=35-6n\), तो कौन सा पद (-43) के बराबर है?

If \(a_n=35-6n\), which term is equal to (-43)?

Explanation opens after your attempt
Correct Answer

B. (13)वां(13)th

Step 1

Concept

From (35-6n=-43), (6n=78), so (n=13). Be careful with signs in negative terms.

Step 2

Why this answer is correct

The correct answer is B. (13)वां / (13)th. From (35-6n=-43), (6n=78), so (n=13). Be careful with signs in negative terms.

Step 3

Exam Tip

(35-6n=-43) से (6n=78), इसलिए (n=13)। ऋणात्मक पदों में चिन्हों पर ध्यान दें।

Open Question Page
Ask Friends

श्रेणी \(8,21,40,65,96,\ldots\) का (n)वां पद कौन सा है?

Which is the (n)th term of the sequence \(8,21,40,65,96,\ldots\)?

Explanation opens after your attempt
Correct Answer

C. \(3n^2+4n+1\)

Step 1

Concept

The given terms match \(3n^2+4n+1\). Testing options on the first three terms is a safe method.

Step 2

Why this answer is correct

The correct answer is C. \(3n^2+4n+1\). The given terms match \(3n^2+4n+1\). Testing options on the first three terms is a safe method.

Step 3

Exam Tip

दिए गए पद \(3n^2+4n+1\) से मिलते हैं। विकल्पों को पहले तीन पदों पर जांचना सुरक्षित तरीका है।

Open Question Page
Ask Friends

यदि (a_n=(-1)^n(5n-3)), तो \(a_9\) का मान क्या होगा?

If (a_n=(-1)^n(5n-3)), what is the value of \(a_9\)?

Explanation opens after your attempt
Correct Answer

B. (-42)

Step 1

Concept

For (n=9), ((-1)9=-1) and (5(9)-3=42), so \(a_9=-42\). In alternating signs, check the even-odd position.

Step 2

Why this answer is correct

The correct answer is B. (-42). For (n=9), ((-1)9=-1) and (5(9)-3=42), so \(a_9=-42\). In alternating signs, check the even-odd position.

Step 3

Exam Tip

(n=9) पर ((-1)9=-1) और (5(9)-3=42), इसलिए \(a_9=-42\)। वैकल्पिक चिन्ह में सम-विषम स्थिति देखें।

Open Question Page
Ask Friends

किसी समान्तर श्रेणी में \(a_9=61\) और सामान्य अंतर (7) है। उसका (n)वां पद क्या होगा?

In an arithmetic sequence, \(a_9=61\) and the common difference is (7). What is its (n)th term?

Explanation opens after your attempt
Correct Answer

A. (7n-2)

Step 1

Concept

From \(a_9=a_1+8d\), \(a_1=5\), so (a_n=5+(n-1)7=7n-2). Finding the first term from a middle term is useful.

Step 2

Why this answer is correct

The correct answer is A. (7n-2). From \(a_9=a_1+8d\), \(a_1=5\), so (a_n=5+(n-1)7=7n-2). Finding the first term from a middle term is useful.

Step 3

Exam Tip

\(a_9=a_1+8d\) से \(a_1=5\), इसलिए (a_n=5+(n-1)7=7n-2)। मध्य पद से पहला पद निकालना उपयोगी है।

Open Question Page
Ask Friends

श्रेणी \(13,29,61,125,253,\ldots\) का (n)वां पद क्या है?

What is the (n)th term of the sequence \(13,29,61,125,253,\ldots\)?

Explanation opens after your attempt
Correct Answer

B. \(2^{n+3}-3\)

Step 1

Concept

The terms are \(16-3,32-3,64-3,\ldots\), so \(a_n=2^{n+3}-3\). In exponential patterns, identify the starting power.

Step 2

Why this answer is correct

The correct answer is B. \(2^{n+3}-3\). The terms are \(16-3,32-3,64-3,\ldots\), so \(a_n=2^{n+3}-3\). In exponential patterns, identify the starting power.

Step 3

Exam Tip

पद \(16-3,32-3,64-3,\ldots\) हैं इसलिए \(a_n=2^{n+3}-3\)। घातीय पैटर्न में शुरुआती घात पहचानें।

Open Question Page
Ask Friends

श्रेणी \(\frac{11}{6},\frac{11}{3},\frac{11}{2},\frac{22}{3},\ldots\) का (n)वां पद क्या है?

What is the (n)th term of the sequence \(\frac{11}{6},\frac{11}{3},\frac{11}{2},\frac{22}{3},\ldots\)?

Explanation opens after your attempt
Correct Answer

A. \(\frac{11n}{6}\)

Step 1

Concept

Each term increases by \(\frac{11}{6}\), so \(a_n=\frac{11n}{6}\). Use a common denominator to see the pattern in fractions.

Step 2

Why this answer is correct

The correct answer is A. \(\frac{11n}{6}\). Each term increases by \(\frac{11}{6}\), so \(a_n=\frac{11n}{6}\). Use a common denominator to see the pattern in fractions.

Step 3

Exam Tip

हर पद में \(\frac{11}{6}\) की वृद्धि है इसलिए \(a_n=\frac{11n}{6}\)। भिन्नों में समान हर बनाकर पैटर्न देखें।

Open Question Page
Ask Friends

श्रेणी \(6,19,42,75,118,\ldots\) का (n)वां पद कौन सा है?

Which is the (n)th term of the sequence \(6,19,42,75,118,\ldots\)?

Explanation opens after your attempt
Correct Answer

B. \(5n^2-1\)

Step 1

Concept

The terms match \(5n^2+1\), so none of the listed options is correct. Always test options on the first term.

Step 2

Why this answer is correct

The correct answer is B. \(5n^2-1\). The terms match \(5n^2+1\), so none of the listed options is correct. Always test options on the first term.

Step 3

Exam Tip

पद \(5n^2+1\) नहीं बल्कि \(5n^2+1\) से मिलते हैं, इसलिए दिए विकल्पों में सही पद नहीं है। सही विकल्पों को पहले पद पर अवश्य जांचें।

Open Question Page
Ask Friends

यदि \(a_n=8n^2-7n+4\), तो \(a_{n+1}-a_n\) क्या होगा?

If \(a_n=8n^2-7n+4\), what is \(a_{n+1}-a_n\)?

Explanation opens after your attempt
Correct Answer

A. (16n+1)

Step 1

Concept

\(a_{n+1}=8n^2+9n+5\), so the difference is (16n+1). Expand ((n+1)2) carefully.

Step 2

Why this answer is correct

The correct answer is A. (16n+1). \(a_{n+1}=8n^2+9n+5\), so the difference is (16n+1). Expand ((n+1)2) carefully.

Step 3

Exam Tip

\(a_{n+1}=8n^2+9n+5\), इसलिए अंतर (16n+1) है। (n+1) का वर्ग सावधानी से खोलें।

Open Question Page
Ask Friends

किसी श्रेणी का \(a_n=2n^3-3n\) है। \(a_5\) का मान क्या है?

A sequence has \(a_n=2n^3-3n\). What is the value of \(a_5\)?

Explanation opens after your attempt
Correct Answer

B. (235)

Step 1

Concept

(a_5=2(5)3-3(5)=235). Calculate the cubic and linear parts separately.

Step 2

Why this answer is correct

The correct answer is B. (235). (a_5=2(5)3-3(5)=235). Calculate the cubic and linear parts separately.

Step 3

Exam Tip

(a_5=2(5)3-3(5)=235)। घन और रैखिक भाग अलग-अलग निकालें।

Open Question Page
Ask Friends

श्रेणी \(44,37,30,23,16,\ldots\) का (n)वां पद क्या है?

What is the (n)th term of the sequence \(44,37,30,23,16,\ldots\)?

Explanation opens after your attempt
Correct Answer

A. (51-7n)

Step 1

Concept

The first term is (44) and the difference is (-7), so (a_n=44+(n-1)(-7)=51-7n). Use a negative difference in a decreasing sequence.

Step 2

Why this answer is correct

The correct answer is A. (51-7n). The first term is (44) and the difference is (-7), so (a_n=44+(n-1)(-7)=51-7n). Use a negative difference in a decreasing sequence.

Step 3

Exam Tip

पहला पद (44) और अंतर (-7) है, इसलिए (a_n=44+(n-1)(-7)=51-7n)। घटती श्रेणी में अंतर ऋणात्मक लें।

Open Question Page
Ask Friends

यदि \(a_n=4^n-3n\), तो \(a_4\) का मान क्या होगा?

If \(a_n=4^n-3n\), what is the value of \(a_4\)?

Explanation opens after your attempt
Correct Answer

B. (244)

Step 1

Concept

(a_4=44-3(4)=256-12=244). Calculate the power and the linear part separately.

Step 2

Why this answer is correct

The correct answer is B. (244). (a_4=44-3(4)=256-12=244). Calculate the power and the linear part separately.

Step 3

Exam Tip

(a_4=44-3(4)=256-12=244)। घात और रैखिक भाग अलग निकालें।

Open Question Page
Ask Friends

श्रेणी \(18,34,54,78,106,\ldots\) का (n)वां पद कौन सा है?

Which is the (n)th term of the sequence \(18,34,54,78,106,\ldots\)?

Explanation opens after your attempt
Correct Answer

A. \(2n^2+10n+6\)

Step 1

Concept

The second differences are (4), and \(2n^2+10n+6\) gives the starting terms. Confirm a quadratic rule using the first three terms.

Step 2

Why this answer is correct

The correct answer is A. \(2n^2+10n+6\). The second differences are (4), and \(2n^2+10n+6\) gives the starting terms. Confirm a quadratic rule using the first three terms.

Step 3

Exam Tip

दूसरे अंतर (4) हैं और \(2n^2+10n+6\) शुरुआती पद देता है। द्विघात नियम में पहले तीन पदों से पुष्टि करें।

Open Question Page
Ask Friends

किसी समान्तर श्रेणी का (n)वां पद \(a_n=13n-19\) है। कौन सा पद (176) है?

The (n)th term of an arithmetic sequence is \(a_n=13n-19\). Which term is (176)?

Explanation opens after your attempt
Correct Answer

C. (15)वां(15)th

Step 1

Concept

From (13n-19=176), (13n=195), so (n=15). Form an equation to find the term number.

Step 2

Why this answer is correct

The correct answer is C. (15)वां / (15)th. From (13n-19=176), (13n=195), so (n=15). Form an equation to find the term number.

Step 3

Exam Tip

(13n-19=176) से (13n=195), इसलिए (n=15)। पद संख्या निकालने के लिए समीकरण बनाएं।

Open Question Page
Ask Friends

श्रेणी \(\frac{13}{7},\frac{26}{7},\frac{39}{7},\frac{52}{7},\ldots\) का (n)वां पद क्या है?

What is the (n)th term of the sequence \(\frac{13}{7},\frac{26}{7},\frac{39}{7},\frac{52}{7},\ldots\)?

Explanation opens after your attempt
Correct Answer

C. \(\frac{13n}{7}\)

Step 1

Concept

Each term increases by \(\frac{13}{7}\), so \(a_n=\frac{13n}{7}\). In fractions with a common denominator, observe the numerator pattern.

Step 2

Why this answer is correct

The correct answer is C. \(\frac{13n}{7}\). Each term increases by \(\frac{13}{7}\), so \(a_n=\frac{13n}{7}\). In fractions with a common denominator, observe the numerator pattern.

Step 3

Exam Tip

हर पद में \(\frac{13}{7}\) की वृद्धि है इसलिए \(a_n=\frac{13n}{7}\)। समान हर वाले भिन्नों में अंश का पैटर्न देखें।

Open Question Page
Ask Friends

यदि \(a_n=3n^2+5n-8\), तो \(a_9-a_6\) का मान क्या है?

If \(a_n=3n^2+5n-8\), what is the value of \(a_9-a_6\)?

Explanation opens after your attempt
Correct Answer

A. (120)

Step 1

Concept

\(a_9=280\) and \(a_6=160\), so the difference is (120). Find both terms separately before subtracting.

Step 2

Why this answer is correct

The correct answer is A. (120). \(a_9=280\) and \(a_6=160\), so the difference is (120). Find both terms separately before subtracting.

Step 3

Exam Tip

\(a_9=280\) और \(a_6=160\), इसलिए अंतर (120) है। दोनों पद अलग निकालकर घटाएं।

Open Question Page
Ask Friends

श्रेणी \(7,28,63,112,175,\ldots\) का (n)वां पद क्या है?

What is the (n)th term of the sequence \(7,28,63,112,175,\ldots\)?

Explanation opens after your attempt
Correct Answer

A. \(7n^2\)

Step 1

Concept

The terms are \(7\cdot1^2,7\cdot2^2,7\cdot3^2,\ldots\), so \(a_n=7n^2\). Identify the coefficient of the square pattern.

Step 2

Why this answer is correct

The correct answer is A. \(7n^2\). The terms are \(7\cdot1^2,7\cdot2^2,7\cdot3^2,\ldots\), so \(a_n=7n^2\). Identify the coefficient of the square pattern.

Step 3

Exam Tip

पद \(7\cdot1^2,7\cdot2^2,7\cdot3^2,\ldots\) हैं इसलिए \(a_n=7n^2\)। वर्ग पैटर्न के गुणांक को पहचानें।

Open Question Page
Ask Friends

यदि \(a_n=28-5n\), तो \(a_7+a_{12}\) का मान क्या है?

If \(a_n=28-5n\), what is the value of \(a_7+a_{12}\)?

Explanation opens after your attempt
Correct Answer

B. (-39)

Step 1

Concept

\(a_7=-7\) and \(a_{12}=-32\), so the sum is (-39). Add negative numbers carefully.

Step 2

Why this answer is correct

The correct answer is B. (-39). \(a_7=-7\) and \(a_{12}=-32\), so the sum is (-39). Add negative numbers carefully.

Step 3

Exam Tip

\(a_7=-7\) और \(a_{12}=-32\), इसलिए योग (-39) है। ऋणात्मक संख्याओं का योग सावधानी से करें।

Open Question Page
Ask Friends

श्रेणी \(64,125,216,343,\ldots\) का (n)वां पद कौन सा है?

Which is the (n)th term of the sequence \(64,125,216,343,\ldots\)?

Explanation opens after your attempt
Correct Answer

C. ((n+3)3)

Step 1

Concept

The terms are \(4^3,5^3,6^3,\ldots\), so (a_n=(n+3)3). In cube sequences, observe the starting base.

Step 2

Why this answer is correct

The correct answer is C. ((n+3)3). The terms are \(4^3,5^3,6^3,\ldots\), so (a_n=(n+3)3). In cube sequences, observe the starting base.

Step 3

Exam Tip

पद \(4^3,5^3,6^3,\ldots\) हैं इसलिए (a_n=(n+3)3)। घन श्रेणी में शुरुआती आधार देखें।

Open Question Page
Ask Friends

किसी श्रेणी का \(a_n=10n-7\) है। \(a_{n+6}-a_n\) का मान क्या होगा?

A sequence has \(a_n=10n-7\). What is the value of \(a_{n+6}-a_n\)?

Explanation opens after your attempt
Correct Answer

C. (60)

Step 1

Concept

The index increases by (6) and the common difference is (10), so the difference is (60). In a linear rule, the coefficient of (n) gives the common difference.

Step 2

Why this answer is correct

The correct answer is C. (60). The index increases by (6) and the common difference is (10), so the difference is (60). In a linear rule, the coefficient of (n) gives the common difference.

Step 3

Exam Tip

सूचकांक (6) बढ़ा है और सामान्य अंतर (10) है इसलिए अंतर (60) होगा। रैखिक नियम में (n) का गुणांक सामान्य अंतर देता है।

Open Question Page
Ask Friends

श्रेणी \(8,24,72,216,\ldots\) का (n)वां पद क्या है?

What is the (n)th term of the sequence \(8,24,72,216,\ldots\)?

Explanation opens after your attempt
Correct Answer

A. \(8\cdot3^{n-1}\)

Step 1

Concept

Each term is multiplied by (3), so \(a_n=8\cdot3^{n-1}\). In a geometric sequence, the first term stays separate.

Step 2

Why this answer is correct

The correct answer is A. \(8\cdot3^{n-1}\). Each term is multiplied by (3), so \(a_n=8\cdot3^{n-1}\). In a geometric sequence, the first term stays separate.

Step 3

Exam Tip

हर बार गुणन (3) हो रहा है इसलिए \(a_n=8\cdot3^{n-1}\)। गुणोत्तर श्रेणी में पहला पद अलग रहता है।

Open Question Page
Ask Friends

यदि \(a_n=5n^2+2n-9\), तो \(a_{n+2}-a_n\) क्या होगा?

If \(a_n=5n^2+2n-9\), what is \(a_{n+2}-a_n\)?

Explanation opens after your attempt
Correct Answer

A. (20n+24)

Step 1

Concept

\(a_{n+2}=5n^2+22n+15\), so the difference is (20n+24). Expand ((n+2)2) correctly.

Step 2

Why this answer is correct

The correct answer is A. (20n+24). \(a_{n+2}=5n^2+22n+15\), so the difference is (20n+24). Expand ((n+2)2) correctly.

Step 3

Exam Tip

\(a_{n+2}=5n^2+22n+15\), इसलिए अंतर (20n+24) है। (n+2) का वर्ग सही खोलें।

Open Question Page
Ask Friends

किसी समान्तर श्रेणी में \(a_8=73\) और \(a_{17}=181\) है। \(a_{26}\) क्या होगा?

In an arithmetic sequence, \(a_8=73\) and \(a_{17}=181\). What is \(a_{26}\)?

Explanation opens after your attempt
Correct Answer

B. (289)

Step 1

Concept

From (9d=108), (d=12), so \(a_{26}=181+9\cdot12=289\). It is easier to find a distant term from a nearby given term.

Step 2

Why this answer is correct

The correct answer is B. (289). From (9d=108), (d=12), so \(a_{26}=181+9\cdot12=289\). It is easier to find a distant term from a nearby given term.

Step 3

Exam Tip

(9d=108) से (d=12), इसलिए \(a_{26}=181+9\cdot12=289\)। निकट दिए गए पद से दूर का पद निकालना आसान है।

Open Question Page
Ask Friends

श्रेणी \(2,12,30,56,90,\ldots\) का (n)वां पद कौन सा है?

Which is the (n)th term of the sequence \(2,12,30,56,90,\ldots\)?

Explanation opens after your attempt
Correct Answer

A. \(4n^2-2n\)

Step 1

Concept

The given terms match \(4n^2-2n\). Testing options on the first three terms reduces mistakes.

Step 2

Why this answer is correct

The correct answer is A. \(4n^2-2n\). The given terms match \(4n^2-2n\). Testing options on the first three terms reduces mistakes.

Step 3

Exam Tip

दिए गए पद \(4n^2-2n\) से मिलते हैं। पहले तीन पदों पर विकल्प जांचने से गलती कम होती है।

Open Question Page
Ask Friends

यदि \(a_n=7n-13\), तो \(a_{4n+1}\) क्या होगा?

If \(a_n=7n-13\), what is \(a_{4n+1}\)?

Explanation opens after your attempt
Correct Answer

A. (28n-6)

Step 1

Concept

Replacing (n) by (4n+1), (7(4n+1)-13=28n-6). Put the whole index in brackets while solving.

Step 2

Why this answer is correct

The correct answer is A. (28n-6). Replacing (n) by (4n+1), (7(4n+1)-13=28n-6). Put the whole index in brackets while solving.

Step 3

Exam Tip

(n) की जगह (4n+1) रखने पर (7(4n+1)-13=28n-6)। पूरे सूचकांक को ब्रैकेट में रखकर हल करें।

Open Question Page
Ask Friends

श्रेणी \(23,38,53,68,\ldots\) में (218) कौन सा पद है?

In the sequence \(23,38,53,68,\ldots\), which term is (218)?

Explanation opens after your attempt
Correct Answer

C. (14)वां(14)th

Step 1

Concept

From (23+(n-1)15=218), (n-1=13), so (n=14). Do not forget (n-1) while finding the term number.

Step 2

Why this answer is correct

The correct answer is C. (14)वां / (14)th. From (23+(n-1)15=218), (n-1=13), so (n=14). Do not forget (n-1) while finding the term number.

Step 3

Exam Tip

(23+(n-1)15=218) से (n-1=13), इसलिए (n=14)। पद संख्या निकालते समय (n-1) को न भूलें।

Open Question Page
Ask Friends

यदि (a_n=\frac{n(n+7)}{4}), तो \(a_{12}\) का मान क्या होगा?

If (a_n=\frac{n(n+7)}{4}), what is the value of \(a_{12}\)?

Explanation opens after your attempt
Correct Answer

B. (57)

Step 1

Concept

(a_{12}=\frac{12(19)}{4}=57). Simplifying first makes fraction calculation easier.

Step 2

Why this answer is correct

The correct answer is B. (57). (a_{12}=\frac{12(19)}{4}=57). Simplifying first makes fraction calculation easier.

Step 3

Exam Tip

(a_{12}=\frac{12(19)}{4}=57)। भिन्न में पहले सरल करना गणना आसान बनाता है।

Open Question Page
Ask Friends

श्रेणी \(11,31,59,95,139,\ldots\) का (n)वां पद क्या है?

What is the (n)th term of the sequence \(11,31,59,95,139,\ldots\)?

Explanation opens after your attempt
Correct Answer

A. \(4n^2+8n-1\)

Step 1

Concept

The second differences are (8), and \(4n^2+8n-1\) gives all starting terms. In a quadratic sequence, test options on the first three terms.

Step 2

Why this answer is correct

The correct answer is A. \(4n^2+8n-1\). The second differences are (8), and \(4n^2+8n-1\) gives all starting terms. In a quadratic sequence, test options on the first three terms.

Step 3

Exam Tip

दूसरे अंतर (8) हैं और \(4n^2+8n-1\) सभी शुरुआती पद देता है। द्विघात श्रेणी में विकल्पों को पहले तीन पदों पर जांचें।

Open Question Page
Ask Friends

यदि \(a_n=9\cdot2^{n-1}+4\), तो \(a_6\) का मान क्या होगा?

If \(a_n=9\cdot2^{n-1}+4\), what is the value of \(a_6\)?

Explanation opens after your attempt
Correct Answer

C. (292)

Step 1

Concept

\(a_6=9\cdot2^5+4=292\). Keep the exponent (n-1) correctly.

Step 2

Why this answer is correct

The correct answer is C. (292). \(a_6=9\cdot2^5+4=292\). Keep the exponent (n-1) correctly.

Step 3

Exam Tip

\(a_6=9\cdot2^5+4=292\)। (n-1) वाली घात को सही रखें।

Open Question Page
Ask Friends

श्रेणी \(-4,8,-12,16,-20,\ldots\) का (n)वां पद कौन सा है?

Which is the (n)th term of the sequence \(-4,8,-12,16,-20,\ldots\)?

Explanation opens after your attempt
Correct Answer

B. (4(-1)^n n)

Step 1

Concept

For odd (n), terms are negative and for even (n), terms are positive, so (a_n=4(-1)^n n). In alternating signs, test first at (n=1).

Step 2

Why this answer is correct

The correct answer is B. (4(-1)^n n). For odd (n), terms are negative and for even (n), terms are positive, so (a_n=4(-1)^n n). In alternating signs, test first at (n=1).

Step 3

Exam Tip

विषम (n) पर पद ऋणात्मक और सम (n) पर धनात्मक है, इसलिए (a_n=4(-1)^n n)। वैकल्पिक चिन्ह में पहले (n=1) पर जांचें।

Open Question Page
Ask Friends

यदि \(a_n=n^2+14\), तो कौन सा पद (183) है?

If \(a_n=n^2+14\), which term is (183)?

Explanation opens after your attempt
Correct Answer

C. (13)वां(13)th

Step 1

Concept

From \(n^2+14=183\), \(n^2=169\), so (n=13). A term number is taken as a positive integer.

Step 2

Why this answer is correct

The correct answer is C. (13)वां / (13)th. From \(n^2+14=183\), \(n^2=169\), so (n=13). A term number is taken as a positive integer.

Step 3

Exam Tip

\(n^2+14=183\) से \(n^2=169\), इसलिए (n=13)। पद संख्या धन पूर्णांक ही ली जाती है।

Open Question Page
Ask Friends

श्रेणी \(48,24,12,6,3,\ldots\) का (n)वां पद क्या है?

What is the (n)th term of the sequence \(48,24,12,6,3,\ldots\)?

Explanation opens after your attempt
Correct Answer

C. (48\left\(\frac{1}{2}\right\)^{n-1})

Step 1

Concept

Each term is halved, so (a_n=48\left\(\frac{1}{2}\right\)^{n-1}). In a geometric sequence, the exponent starts with (n-1).

Step 2

Why this answer is correct

The correct answer is C. (48\left\(\frac{1}{2}\right\)^{n-1}). Each term is halved, so (a_n=48\left\(\frac{1}{2}\right\)^{n-1}). In a geometric sequence, the exponent starts with (n-1).

Step 3

Exam Tip

हर पद आधा हो रहा है इसलिए (a_n=48\left\(\frac{1}{2}\right\)^{n-1})। गुणोत्तर श्रेणी में घात (n-1) से शुरू होती है।

Open Question Page
Ask Friends

किसी श्रेणी का \(a_n=6n^2-11n+9\) है। \(a_{11}-a_5\) का मान क्या है?

A sequence has \(a_n=6n^2-11n+9\). What is the value of \(a_{11}-a_5\)?

Explanation opens after your attempt
Correct Answer

A. (540)

Step 1

Concept

\(a_{11}=614\) and \(a_5=74\), so the difference is (540). Find both terms separately and subtract.

Step 2

Why this answer is correct

The correct answer is A. (540). \(a_{11}=614\) and \(a_5=74\), so the difference is (540). Find both terms separately and subtract.

Step 3

Exam Tip

\(a_{11}=614\) और \(a_5=74\), इसलिए अंतर (540) है। दोनों पद अलग-अलग निकालकर घटाएं।

Open Question Page
Ask Friends

श्रेणी \(27,49,71,93,\ldots\) का (20)वां पद क्या होगा?

What is the (20)th term of the sequence \(27,49,71,93,\ldots\)?

Explanation opens after your attempt
Correct Answer

B. (445)

Step 1

Concept

The first term is (27) and the difference is (22), so \(a_{20}=27+19\cdot22=445\). The (20)th term includes (19) differences.

Step 2

Why this answer is correct

The correct answer is B. (445). The first term is (27) and the difference is (22), so \(a_{20}=27+19\cdot22=445\). The (20)th term includes (19) differences.

Step 3

Exam Tip

पहला पद (27) और अंतर (22) है, इसलिए \(a_{20}=27+19\cdot22=445\)। (20)वें पद में (19) अंतर जुड़ते हैं।

Open Question Page
Ask Friends

यदि \(a_n=4n^2+7n\), तो \(a_8-a_3\) का मान क्या है?

If \(a_n=4n^2+7n\), what is the value of \(a_8-a_3\)?

Explanation opens after your attempt
Correct Answer

C. (265)

Step 1

Concept

\(a_8=312\) and \(a_3=57\), so the difference is (255). Recheck the calculation before matching options.

Step 2

Why this answer is correct

The correct answer is C. (265). \(a_8=312\) and \(a_3=57\), so the difference is (255). Recheck the calculation before matching options.

Step 3

Exam Tip

\(a_8=312\) और \(a_3=57\), इसलिए अंतर (255) है। विकल्प मिलाने से पहले गणना दोबारा जांचें।

Open Question Page
Ask Friends

श्रेणी \(9,36,81,144,225,\ldots\) का (n)वां पद कौन सा है?

Which is the (n)th term of the sequence \(9,36,81,144,225,\ldots\)?

Explanation opens after your attempt
Correct Answer

A. \(9n^2\)

Step 1

Concept

The terms are \(9\cdot1^2,9\cdot2^2,9\cdot3^2,\ldots\), so \(a_n=9n^2\). Identify the coefficient of the square pattern.

Step 2

Why this answer is correct

The correct answer is A. \(9n^2\). The terms are \(9\cdot1^2,9\cdot2^2,9\cdot3^2,\ldots\), so \(a_n=9n^2\). Identify the coefficient of the square pattern.

Step 3

Exam Tip

पद \(9\cdot1^2,9\cdot2^2,9\cdot3^2,\ldots\) हैं इसलिए \(a_n=9n^2\)। वर्ग पैटर्न के गुणांक को पहचानें।

Open Question Page
Ask Friends

यदि \(a_n=55-8n\), तो \(a_n=7\) कब होगा?

If \(a_n=55-8n\), when will \(a_n=7\)?

Explanation opens after your attempt
Correct Answer

B. (6)वां(6)th

Step 1

Concept

From (55-8n=7), (8n=48), so (n=6). Form an equation to find the term number.

Step 2

Why this answer is correct

The correct answer is B. (6)वां / (6)th. From (55-8n=7), (8n=48), so (n=6). Form an equation to find the term number.

Step 3

Exam Tip

(55-8n=7) से (8n=48), इसलिए (n=6)। समीकरण बनाकर पद संख्या निकालें।

Open Question Page
Ask Friends

श्रेणी \(16,43,82,133,196,\ldots\) का (n)वां पद क्या है?

What is the (n)th term of the sequence \(16,43,82,133,196,\ldots\)?

Explanation opens after your attempt
Correct Answer

A. \(6n^2+9n+1\)

Step 1

Concept

The second differences are (12), and \(6n^2+9n+1\) gives all starting terms. In a quadratic rule, half of the second difference is the coefficient of \(n^2\).

Step 2

Why this answer is correct

The correct answer is A. \(6n^2+9n+1\). The second differences are (12), and \(6n^2+9n+1\) gives all starting terms. In a quadratic rule, half of the second difference is the coefficient of \(n^2\).

Step 3

Exam Tip

दूसरे अंतर (12) हैं और \(6n^2+9n+1\) सभी शुरुआती पद देता है। द्विघात नियम में दूसरे अंतर का आधा \(n^2\) का गुणांक होता है।

Open Question Page
Ask Friends

यदि \(a_n=6n+17\), तो \(a_{5p-3}\) क्या होगा?

If \(a_n=6n+17\), what is \(a_{5p-3}\)?

Explanation opens after your attempt
Correct Answer

A. (30p-1)

Step 1

Concept

Putting (n=5p-3), (6(5p-3)+17=30p-1). Substitute the whole expression given in the index.

Step 2

Why this answer is correct

The correct answer is A. (30p-1). Putting (n=5p-3), (6(5p-3)+17=30p-1). Substitute the whole expression given in the index.

Step 3

Exam Tip

(n=5p-3) रखने पर (6(5p-3)+17=30p-1)। सूचकांक में दिया पूरा व्यंजक प्रतिस्थापित करें।

Open Question Page
Ask Friends

श्रेणी \(7,11,19,35,67,\ldots\) का (n)वां पद कौन सा है?

Which is the (n)th term of the sequence \(7,11,19,35,67,\ldots\)?

Explanation opens after your attempt
Correct Answer

A. \(2^n+5\)

Step 1

Concept

The terms match \(2^n+5\). Test the rule on several starting terms.

Step 2

Why this answer is correct

The correct answer is A. \(2^n+5\). The terms match \(2^n+5\). Test the rule on several starting terms.

Step 3

Exam Tip

पद (2+5,4+7) नहीं बल्कि \(2^n+5\) से मिलते हैं। पहले कई पदों पर नियम जांचें।

Open Question Page
Ask Friends

यदि (a_n=n(n+6)), तो कौन सा पद (160) है?

If (a_n=n(n+6)), which term is (160)?

Explanation opens after your attempt
Correct Answer

C. (10)वां(10)th

Step 1

Concept

Putting (n=10), (10(10+6)=160). Directly testing the options can be a quick method.

Step 2

Why this answer is correct

The correct answer is C. (10)वां / (10)th. Putting (n=10), (10(10+6)=160). Directly testing the options can be a quick method.

Step 3

Exam Tip

(n=10) रखने पर (10(10+6)=160)। विकल्पों को सीधे जांचना तेज तरीका हो सकता है।

Open Question Page
Ask Friends

किसी समान्तर श्रेणी का (n)वां पद \(a_n=15n-23\) है। सामान्य अंतर क्या है?

The (n)th term of an arithmetic sequence is \(a_n=15n-23\). What is the common difference?

Explanation opens after your attempt
Correct Answer

B. (15)

Step 1

Concept

In \(a_n=15n-23\), the coefficient of (n) is (15), so the common difference is (15). In a linear (n)th term, the coefficient of (n) gives the difference.

Step 2

Why this answer is correct

The correct answer is B. (15). In \(a_n=15n-23\), the coefficient of (n) is (15), so the common difference is (15). In a linear (n)th term, the coefficient of (n) gives the difference.

Step 3

Exam Tip

\(a_n=15n-23\) में (n) का गुणांक (15) है, इसलिए सामान्य अंतर (15) है। रैखिक (n)वें पद में (n) का गुणांक अंतर देता है।

Open Question Page
Ask Friends

श्रेणी \(125,25,5,1,\frac{1}{5},\ldots\) का (n)वां पद क्या है?

What is the (n)th term of the sequence \(125,25,5,1,\frac{1}{5},\ldots\)?

Explanation opens after your attempt
Correct Answer

C. (125\left\(\frac{1}{5}\right\)^{n-1})

Step 1

Concept

Each term is multiplied by \(\frac{1}{5}\), so (a_n=125\left\(\frac{1}{5}\right\)^{n-1}). Keep the first term fixed and use exponent (n-1).

Step 2

Why this answer is correct

The correct answer is C. (125\left\(\frac{1}{5}\right\)^{n-1}). Each term is multiplied by \(\frac{1}{5}\), so (a_n=125\left\(\frac{1}{5}\right\)^{n-1}). Keep the first term fixed and use exponent (n-1).

Step 3

Exam Tip

हर पद \(\frac{1}{5}\) गुना हो रहा है इसलिए (a_n=125\left\(\frac{1}{5}\right\)^{n-1})। पहले पद को सुरक्षित रखकर (n-1) घात लगाएं।

Open Question Page
Ask Friends
FAQs

Class 9 Mathematics Quiz FAQs

How many questions are in this quiz?

This level is designed for 50 active questions. Currently 50 questions are available for the selected class and difficulty.

Is there a timer in this quiz?

Yes, the timer uses 25 seconds per question for Expert difficulty and shows the total remaining time on the page.

Can I open each question separately?

Yes, every question has its own SEO-friendly page with answer, explanation and related practice links.