Class 9 Mathematics - Sequences and Progressions - Sum of first n natural numbers Easy Quiz

Mathematics Sequences and Progressions Sum of first n natural numbers Easy Class 9 Level 63

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Question 1/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 63

पहली (15) प्राकृतिक संख्याओं का योग ज्ञात कीजिए।

Find the sum of the first (15) natural numbers.

Explanation opens after your attempt
Correct Answer

C. (120)

Step 1

Concept

\(S_{15}=\frac{15\times16}{2}=120\). Cancelling by (2) before multiplication makes it easier.

Step 2

Why this answer is correct

The correct answer is C. (120). \(S_{15}=\frac{15\times16}{2}=120\). Cancelling by (2) before multiplication makes it easier.

Step 3

Exam Tip

\(S_{15}=\frac{15\times16}{2}=120\) होता है। गुणा करने से पहले (2) से काटना आसान रहता है।

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Question 2/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 63

\(1+2+3+\cdots+20\) का मान क्या होगा?

What is the value of \(1+2+3+\cdots+20\)?

Explanation opens after your attempt
Correct Answer

A. (210)

Step 1

Concept

This is the sum of the first (20) natural numbers, so \(S_{20}=210\). The dots \(\cdots\) show that the sequence continues.

Step 2

Why this answer is correct

The correct answer is A. (210). This is the sum of the first (20) natural numbers, so \(S_{20}=210\). The dots \(\cdots\) show that the sequence continues.

Step 3

Exam Tip

यह पहली (20) प्राकृतिक संख्याओं का योग है इसलिए \(S_{20}=210\)। बिंदुओं वाला \(\cdots\) क्रम जारी रहने का संकेत देता है।

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Question 3/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 63

पहली (7) प्राकृतिक संख्याओं का योग कौन सा है?

Which is the sum of the first (7) natural numbers?

Explanation opens after your attempt
Correct Answer

D. (28)

Step 1

Concept

(1+2+3+4+5+6+7=28). For small (n), direct addition is also useful.

Step 2

Why this answer is correct

The correct answer is D. (28). (1+2+3+4+5+6+7=28). For small (n), direct addition is also useful.

Step 3

Exam Tip

(1+2+3+4+5+6+7=28) होता है। छोटे (n) में सीधे जोड़ना भी उपयोगी है।

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Question 4/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 63

यदि पहली (n) प्राकृतिक संख्याओं का योग (45) है तो (n) क्या है?

If the sum of the first (n) natural numbers is (45), what is (n)?

Explanation opens after your attempt
Correct Answer

B. (9)

Step 1

Concept

\(S_9=\frac{9\times10}{2}=45\), so (n=9). In such questions, checking options in the formula is fast.

Step 2

Why this answer is correct

The correct answer is B. (9). \(S_9=\frac{9\times10}{2}=45\), so (n=9). In such questions, checking options in the formula is fast.

Step 3

Exam Tip

\(S_9=\frac{9\times10}{2}=45\) इसलिए (n=9)। ऐसे प्रश्नों में विकल्पों को सूत्र में रखकर जांचना तेज होता है।

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Question 5/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 63

पहली (12) प्राकृतिक संख्याओं का योग कितना होगा?

What will be the sum of the first (12) natural numbers?

Explanation opens after your attempt
Correct Answer

C. (78)

Step 1

Concept

\(S_{12}=\frac{12\times13}{2}=78\). Dividing (12) by (2) first simplifies the calculation.

Step 2

Why this answer is correct

The correct answer is C. (78). \(S_{12}=\frac{12\times13}{2}=78\). Dividing (12) by (2) first simplifies the calculation.

Step 3

Exam Tip

\(S_{12}=\frac{12\times13}{2}=78\) है। पहले (12) को (2) से भाग देने पर गणना सरल हो जाती है।

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Question 6/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 63

एक छात्र पहले (18) प्राकृतिक संख्याएँ जोड़ता है। सही योग क्या आएगा?

A student adds the first (18) natural numbers. What is the correct sum?

Explanation opens after your attempt
Correct Answer

A. (171)

Step 1

Concept

\(S_{18}=\frac{18\times19}{2}=171\). Natural numbers start from (1).

Step 2

Why this answer is correct

The correct answer is A. (171). \(S_{18}=\frac{18\times19}{2}=171\). Natural numbers start from (1).

Step 3

Exam Tip

\(S_{18}=\frac{18\times19}{2}=171\) होता है। प्राकृतिक संख्याएँ (1) से शुरू होती हैं।

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Question 7/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 63

(1) से (25) तक की सभी प्राकृतिक संख्याओं का योग ज्ञात करें।

Find the sum of all natural numbers from (1) to (25).

Explanation opens after your attempt
Correct Answer

B. (325)

Step 1

Concept

\(S_{25}=\frac{25\times26}{2}=325\). From (1) to (25) means the first (25) natural numbers.

Step 2

Why this answer is correct

The correct answer is B. (325). \(S_{25}=\frac{25\times26}{2}=325\). From (1) to (25) means the first (25) natural numbers.

Step 3

Exam Tip

\(S_{25}=\frac{25\times26}{2}=325\) है। (1) से (25) तक का अर्थ पहली (25) प्राकृतिक संख्याएँ है।

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Question 8/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 63

पहली (5) प्राकृतिक संख्याओं का योग कितना है?

What is the sum of the first (5) natural numbers?

Explanation opens after your attempt
Correct Answer

C. (15)

Step 1

Concept

(1+2+3+4+5=15). Even in small questions, start the sequence from (1).

Step 2

Why this answer is correct

The correct answer is C. (15). (1+2+3+4+5=15). Even in small questions, start the sequence from (1).

Step 3

Exam Tip

(1+2+3+4+5=15) होता है। छोटे प्रश्नों में भी क्रम (1) से ही शुरू करें।

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Question 9/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 63

किस (n) के लिए पहली (n) प्राकृतिक संख्याओं का योग (66) होगा?

For which (n) will the sum of the first (n) natural numbers be (66)?

Explanation opens after your attempt
Correct Answer

D. (12)

Step 1

Concept

\(S_{11}=66\) because \(\frac{11\times12}{2}=66\). Substitute the options for (n) and match.

Step 2

Why this answer is correct

The correct answer is D. (12). \(S_{11}=66\) because \(\frac{11\times12}{2}=66\). Substitute the options for (n) and match.

Step 3

Exam Tip

\(S_{11}=66\) क्योंकि \(\frac{11\times12}{2}=66\)। विकल्पों में (n) रखकर मिलान करें।

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Question 10/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 63

यदि (S_n=\frac{n(n+1)}{2}) है तो \(S_6\) का मान क्या है?

If (S_n=\frac{n(n+1)}{2}), what is the value of \(S_6\)?

Explanation opens after your attempt
Correct Answer

B. (21)

Step 1

Concept

\(S_6=\frac{6\times7}{2}=21\). Put the given number in place of (n) in the formula.

Step 2

Why this answer is correct

The correct answer is B. (21). \(S_6=\frac{6\times7}{2}=21\). Put the given number in place of (n) in the formula.

Step 3

Exam Tip

\(S_6=\frac{6\times7}{2}=21\) है। सूत्र में (n) की जगह दी गई संख्या रखें।

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Question 11/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 63

पहली (30) प्राकृतिक संख्याओं का योग चुनिए।

Choose the sum of the first (30) natural numbers.

Explanation opens after your attempt
Correct Answer

D. (465)

Step 1

Concept

\(S_{30}=\frac{30\times31}{2}=465\). Halve (30) and calculate \(15\times31\).

Step 2

Why this answer is correct

The correct answer is D. (465). \(S_{30}=\frac{30\times31}{2}=465\). Halve (30) and calculate \(15\times31\).

Step 3

Exam Tip

\(S_{30}=\frac{30\times31}{2}=465\) है। (30) को आधा करके \(15\times31\) करें।

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Question 12/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 63

\(1+2+3+\cdots+14\) का योग कितना है?

What is the sum of \(1+2+3+\cdots+14\)?

Explanation opens after your attempt
Correct Answer

A. (105)

Step 1

Concept

This is \(S_{14}\), and \(S_{14}=\frac{14\times15}{2}=105\). The last term (14) is (n).

Step 2

Why this answer is correct

The correct answer is A. (105). This is \(S_{14}\), and \(S_{14}=\frac{14\times15}{2}=105\). The last term (14) is (n).

Step 3

Exam Tip

यह \(S_{14}\) है और \(S_{14}=\frac{14\times15}{2}=105\)। अंतिम पद (14) ही (n) है।

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Question 13/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 63

पहली (9) प्राकृतिक संख्याओं का योग किसके बराबर है?

The sum of the first (9) natural numbers is equal to which value?

Explanation opens after your attempt
Correct Answer

C. (45)

Step 1

Concept

\(S_9=\frac{9\times10}{2}=45\). Remember that adding up to (9) uses the factor (10).

Step 2

Why this answer is correct

The correct answer is C. (45). \(S_9=\frac{9\times10}{2}=45\). Remember that adding up to (9) uses the factor (10).

Step 3

Exam Tip

\(S_9=\frac{9\times10}{2}=45\) होता है। याद रखें (9) तक जोड़ने में (10) गुणक आता है।

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Question 14/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 63

\(1+2+3+\cdots+n\) का सामान्य सूत्र कौन सा है?

Which is the general formula for \(1+2+3+\cdots+n\)?

Explanation opens after your attempt
Correct Answer

D. (\frac{n(n+1)}{2})

Step 1

Concept

The sum of the first (n) natural numbers is (S_n=\frac{n(n+1)}{2}). This formula is the key formula of this topic.

Step 2

Why this answer is correct

The correct answer is D. (\frac{n(n+1)}{2}). The sum of the first (n) natural numbers is (S_n=\frac{n(n+1)}{2}). This formula is the key formula of this topic.

Step 3

Exam Tip

पहली (n) प्राकृतिक संख्याओं का योग (S_n=\frac{n(n+1)}{2}) होता है। यह सूत्र इस अध्याय का मूल सूत्र है।

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Question 15/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 63

यदि \(S_8\) पहली (8) प्राकृतिक संख्याओं का योग है तो \(S_8\) क्या है?

If \(S_8\) is the sum of the first (8) natural numbers, what is \(S_8\)?

Explanation opens after your attempt
Correct Answer

A. (36)

Step 1

Concept

\(S_8=\frac{8\times9}{2}=36\). The subscript in \(S_n\) shows the number of terms.

Step 2

Why this answer is correct

The correct answer is A. (36). \(S_8=\frac{8\times9}{2}=36\). The subscript in \(S_n\) shows the number of terms.

Step 3

Exam Tip

\(S_8=\frac{8\times9}{2}=36\) है। \(S_n\) में नीचे की संख्या पदों की संख्या बताती है।

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Question 16/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 63

एक पंक्ति में (1), दूसरी में (2), और इसी तरह (11)वीं पंक्ति तक बिंदु रखे गए। कुल बिंदु कितने होंगे?

Dots are placed with (1) in the first row, (2) in the second row, and so on up to the (11)th row. How many dots are there in total?

Explanation opens after your attempt
Correct Answer

B. (66)

Step 1

Concept

The total dots are \(1+2+\cdots+11=66\). Such an arrangement forms the sum of natural numbers.

Step 2

Why this answer is correct

The correct answer is B. (66). The total dots are \(1+2+\cdots+11=66\). Such an arrangement forms the sum of natural numbers.

Step 3

Exam Tip

कुल बिंदु \(1+2+\cdots+11=66\) होंगे। ऐसी व्यवस्था में प्राकृतिक संख्याओं का योग बनता है।

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Question 17/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 63

पहले (16) दिनों में एक विद्यार्थी रोज क्रमशः (1), (2), (3) पेज पढ़ता है। कुल कितने पेज पढ़ेगा?

In the first (16) days, a student reads (1), (2), (3) pages respectively each day. How many pages will be read in total?

Explanation opens after your attempt
Correct Answer

C. (136)

Step 1

Concept

Total pages will be \(S_{16}=\frac{16\times17}{2}=136\). Notice the pages increasing one by one in the question.

Step 2

Why this answer is correct

The correct answer is C. (136). Total pages will be \(S_{16}=\frac{16\times17}{2}=136\). Notice the pages increasing one by one in the question.

Step 3

Exam Tip

कुल पेज \(S_{16}=\frac{16\times17}{2}=136\) होंगे। प्रश्न में क्रमशः बढ़ते पेज देखें।

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Question 18/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 63

पहली (4) प्राकृतिक संख्याओं का योग क्या है?

What is the sum of the first (4) natural numbers?

Explanation opens after your attempt
Correct Answer

D. (10)

Step 1

Concept

(1+2+3+4=10). Natural numbers in this topic are not counted from (0).

Step 2

Why this answer is correct

The correct answer is D. (10). (1+2+3+4=10). Natural numbers in this topic are not counted from (0).

Step 3

Exam Tip

(1+2+3+4=10) है। प्राकृतिक संख्याओं की गिनती (0) से नहीं होती।

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Question 19/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 63

यदि पहली (n) प्राकृतिक संख्याओं का योग (91) है तो (n) चुनिए।

If the sum of the first (n) natural numbers is (91), choose (n).

Explanation opens after your attempt
Correct Answer

B. (13)

Step 1

Concept

\(S_{13}=\frac{13\times14}{2}=91\), so (n=13). Check nearby sums to identify the correct (n).

Step 2

Why this answer is correct

The correct answer is B. (13). \(S_{13}=\frac{13\times14}{2}=91\), so (n=13). Check nearby sums to identify the correct (n).

Step 3

Exam Tip

\(S_{13}=\frac{13\times14}{2}=91\) इसलिए (n=13)। सही (n) पहचानने के लिए आसपास के योग जांचें।

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Question 20/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 63

(1) से (19) तक की प्राकृतिक संख्याओं का योग कितना है?

What is the sum of natural numbers from (1) to (19)?

Explanation opens after your attempt
Correct Answer

C. (190)

Step 1

Concept

\(S_{19}=\frac{19\times20}{2}=190\). When the last number is (19), take (n=19).

Step 2

Why this answer is correct

The correct answer is C. (190). \(S_{19}=\frac{19\times20}{2}=190\). When the last number is (19), take (n=19).

Step 3

Exam Tip

\(S_{19}=\frac{19\times20}{2}=190\) होता है। जब अंतिम संख्या (19) हो तो (n=19) लें।

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Question 21/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 63

पहली (2) प्राकृतिक संख्याओं का योग क्या होगा?

What will be the sum of the first (2) natural numbers?

Explanation opens after your attempt
Correct Answer

B. (3)

Step 1

Concept

The first (2) natural numbers are (1) and (2), so the sum is (3). Listing terms is safe in basic questions.

Step 2

Why this answer is correct

The correct answer is B. (3). The first (2) natural numbers are (1) and (2), so the sum is (3). Listing terms is safe in basic questions.

Step 3

Exam Tip

पहली (2) प्राकृतिक संख्याएँ (1) और (2) हैं इसलिए योग (3) है। आधारभूत प्रश्नों में सूची बनाना सुरक्षित रहता है।

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Question 22/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 63

एक सीढ़ी में ऊपर जाते हुए (1), (2), (3) करके (10) ईंटों तक परतें हैं। कुल ईंटें कितनी हैं?

A staircase has layers of (1), (2), (3) bricks up to (10) bricks. How many bricks are there in total?

Explanation opens after your attempt
Correct Answer

C. (55)

Step 1

Concept

Total bricks are \(1+2+\cdots+10=55\). Stair-like patterns often use \(S_n\).

Step 2

Why this answer is correct

The correct answer is C. (55). Total bricks are \(1+2+\cdots+10=55\). Stair-like patterns often use \(S_n\).

Step 3

Exam Tip

कुल ईंटें \(1+2+\cdots+10=55\) हैं। सीढ़ी जैसे पैटर्न में अक्सर \(S_n\) लगता है।

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Question 23/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 63

पहली (22) प्राकृतिक संख्याओं का योग ज्ञात करें।

Find the sum of the first (22) natural numbers.

Explanation opens after your attempt
Correct Answer

A. (253)

Step 1

Concept

\(S_{22}=\frac{22\times23}{2}=253\). Halve the even number (22) and calculate \(11\times23\).

Step 2

Why this answer is correct

The correct answer is A. (253). \(S_{22}=\frac{22\times23}{2}=253\). Halve the even number (22) and calculate \(11\times23\).

Step 3

Exam Tip

\(S_{22}=\frac{22\times23}{2}=253\) है। सम संख्या (22) को आधा करके \(11\times23\) करें।

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Question 24/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 63

यदि \(1+2+3+\cdots+n=28\) है तो (n) का मान क्या है?

If \(1+2+3+\cdots+n=28\), what is the value of (n)?

Explanation opens after your attempt
Correct Answer

B. (7)

Step 1

Concept

\(S_7=28\) because \(\frac{7\times8}{2}=28\). Choose the nearby natural number by observing the sum.

Step 2

Why this answer is correct

The correct answer is B. (7). \(S_7=28\) because \(\frac{7\times8}{2}=28\). Choose the nearby natural number by observing the sum.

Step 3

Exam Tip

\(S_7=28\) क्योंकि \(\frac{7\times8}{2}=28\)। योग देखकर निकट प्राकृतिक संख्या चुनें।

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Question 25/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 63

पहली (17) प्राकृतिक संख्याओं का योग कौन सा है?

Which is the sum of the first (17) natural numbers?

Explanation opens after your attempt
Correct Answer

C. (153)

Step 1

Concept

\(S_{17}=\frac{17\times18}{2}=153\). For odd (n), divide the next even factor by (2).

Step 2

Why this answer is correct

The correct answer is C. (153). \(S_{17}=\frac{17\times18}{2}=153\). For odd (n), divide the next even factor by (2).

Step 3

Exam Tip

\(S_{17}=\frac{17\times18}{2}=153\) है। विषम (n) में अगले सम गुणक को (2) से काटें।

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Question 26/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 63

\(1+2+3+\cdots+50\) का योग क्या होगा?

What will be the sum of \(1+2+3+\cdots+50\)?

Explanation opens after your attempt
Correct Answer

D. (1275)

Step 1

Concept

\(S_{50}=\frac{50\times51}{2}=1275\). For larger (n), apply the formula directly.

Step 2

Why this answer is correct

The correct answer is D. (1275). \(S_{50}=\frac{50\times51}{2}=1275\). For larger (n), apply the formula directly.

Step 3

Exam Tip

\(S_{50}=\frac{50\times51}{2}=1275\) होता है। बड़े (n) में सूत्र सीधे लगाएं।

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Question 27/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 63

किसका मान पहली (24) प्राकृतिक संख्याओं के योग के बराबर है?

Which value is equal to the sum of the first (24) natural numbers?

Explanation opens after your attempt
Correct Answer

C. (300)

Step 1

Concept

\(S_{24}=\frac{24\times25}{2}=300\). Take half of (24) as (12) and calculate \(12\times25\).

Step 2

Why this answer is correct

The correct answer is C. (300). \(S_{24}=\frac{24\times25}{2}=300\). Take half of (24) as (12) and calculate \(12\times25\).

Step 3

Exam Tip

\(S_{24}=\frac{24\times25}{2}=300\) है। (24) का आधा (12) लेकर \(12\times25\) करें।

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Question 28/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 63

यदि \(S_n=120\) और \(S_n\) पहली (n) प्राकृतिक संख्याओं का योग है तो (n) क्या होगा?

If \(S_n=120\) and \(S_n\) is the sum of the first (n) natural numbers, what is (n)?

Explanation opens after your attempt
Correct Answer

C. (15)

Step 1

Concept

\(S_{15}=120\) because \(\frac{15\times16}{2}=120\). In such questions, verify the answer back in the formula.

Step 2

Why this answer is correct

The correct answer is C. (15). \(S_{15}=120\) because \(\frac{15\times16}{2}=120\). In such questions, verify the answer back in the formula.

Step 3

Exam Tip

\(S_{15}=120\) क्योंकि \(\frac{15\times16}{2}=120\)। ऐसे प्रश्नों में उत्तर को वापस सूत्र में जांचें।

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Question 29/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 63

पहली (40) प्राकृतिक संख्याओं का योग कितना है?

What is the sum of the first (40) natural numbers?

Explanation opens after your attempt
Correct Answer

C. (820)

Step 1

Concept

\(S_{40}=\frac{40\times41}{2}=820\). Divide (40) by (2) and calculate \(20\times41\).

Step 2

Why this answer is correct

The correct answer is C. (820). \(S_{40}=\frac{40\times41}{2}=820\). Divide (40) by (2) and calculate \(20\times41\).

Step 3

Exam Tip

\(S_{40}=\frac{40\times41}{2}=820\) है। (40) को (2) से भाग देकर \(20\times41\) करें।

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Question 30/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 63

एक प्रतियोगिता में (1)वें स्थान को (1) अंक, (2)वें को (2) अंक और (13)वें को (13) अंक दिए गए। कुल अंक कितने हुए?

In a competition, (1) point is given for rank (1), (2) points for rank (2), and (13) points for rank (13). What is the total score?

Explanation opens after your attempt
Correct Answer

C. (91)

Step 1

Concept

The total score is \(1+2+\cdots+13=91\). The last rank gives the value of (n).

Step 2

Why this answer is correct

The correct answer is C. (91). The total score is \(1+2+\cdots+13=91\). The last rank gives the value of (n).

Step 3

Exam Tip

कुल अंक \(1+2+\cdots+13=91\) हैं। अंतिम क्रम संख्या ही (n) का मान देती है।

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Question 31/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 63

पहली (21) प्राकृतिक संख्याओं के योग का मान चुनिए।

Choose the value of the sum of the first (21) natural numbers.

Explanation opens after your attempt
Correct Answer

B. (231)

Step 1

Concept

\(S_{21}=\frac{21\times22}{2}=231\). Divide the next even factor (22) by (2) first.

Step 2

Why this answer is correct

The correct answer is B. (231). \(S_{21}=\frac{21\times22}{2}=231\). Divide the next even factor (22) by (2) first.

Step 3

Exam Tip

\(S_{21}=\frac{21\times22}{2}=231\) है। अगले सम गुणक (22) को पहले (2) से भाग दें।

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Question 32/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 63

(1) से (35) तक की प्राकृतिक संख्याओं का योग क्या है?

What is the sum of natural numbers from (1) to (35)?

Explanation opens after your attempt
Correct Answer

C. (630)

Step 1

Concept

\(S_{35}=\frac{35\times36}{2}=630\). Take the last number (35) as (n).

Step 2

Why this answer is correct

The correct answer is C. (630). \(S_{35}=\frac{35\times36}{2}=630\). Take the last number (35) as (n).

Step 3

Exam Tip

\(S_{35}=\frac{35\times36}{2}=630\) है। अंतिम संख्या (35) को (n) मानें।

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Question 33/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 63

यदि \(1+2+3+\cdots+n=210\) है तो (n) क्या है?

If \(1+2+3+\cdots+n=210\), what is (n)?

Explanation opens after your attempt
Correct Answer

C. (20)

Step 1

Concept

\(S_{20}=\frac{20\times21}{2}=210\), so (n=20). For a larger sum, checking through options is simple.

Step 2

Why this answer is correct

The correct answer is C. (20). \(S_{20}=\frac{20\times21}{2}=210\), so (n=20). For a larger sum, checking through options is simple.

Step 3

Exam Tip

\(S_{20}=\frac{20\times21}{2}=210\) इसलिए (n=20)। बड़े योग में विकल्प से जांच करना सरल है।

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Question 34/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 63

एक चार्ट में (1) से (23) तक के नंबर लिखे हैं। सभी नंबरों का योग कितना है?

A chart has numbers from (1) to (23). What is the sum of all the numbers?

Explanation opens after your attempt
Correct Answer

C. (276)

Step 1

Concept

The sum of all numbers is \(S_{23}=\frac{23\times24}{2}=276\). When numbers start consecutively from (1), use \(S_n\).

Step 2

Why this answer is correct

The correct answer is C. (276). The sum of all numbers is \(S_{23}=\frac{23\times24}{2}=276\). When numbers start consecutively from (1), use \(S_n\).

Step 3

Exam Tip

सभी नंबरों का योग \(S_{23}=\frac{23\times24}{2}=276\) है। लगातार (1) से शुरू होने पर \(S_n\) लगाएं।

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Question 35/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 63

पहली (28) प्राकृतिक संख्याओं का योग कौन सा है?

Which is the sum of the first (28) natural numbers?

Explanation opens after your attempt
Correct Answer

B. (406)

Step 1

Concept

\(S_{28}=\frac{28\times29}{2}=406\). Take half of (28) as (14) and calculate \(14\times29\).

Step 2

Why this answer is correct

The correct answer is B. (406). \(S_{28}=\frac{28\times29}{2}=406\). Take half of (28) as (14) and calculate \(14\times29\).

Step 3

Exam Tip

\(S_{28}=\frac{28\times29}{2}=406\) होता है। (28) का आधा (14) लेकर \(14\times29\) करें।

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Question 36/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 63

यदि \(S_{29}\) पहली (29) प्राकृतिक संख्याओं का योग है तो \(S_{29}\) का मान क्या है?

If \(S_{29}\) is the sum of the first (29) natural numbers, what is the value of \(S_{29}\)?

Explanation opens after your attempt
Correct Answer

C. (435)

Step 1

Concept

\(S_{29}=\frac{29\times30}{2}=435\). For odd (n), halve the next term and multiply.

Step 2

Why this answer is correct

The correct answer is C. (435). \(S_{29}=\frac{29\times30}{2}=435\). For odd (n), halve the next term and multiply.

Step 3

Exam Tip

\(S_{29}=\frac{29\times30}{2}=435\) है। विषम (n) में अगले पद को आधा करके गुणा करें।

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Question 37/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 63

\(1+2+3+\cdots+34\) का सही योग चुनिए।

Choose the correct sum of \(1+2+3+\cdots+34\).

Explanation opens after your attempt
Correct Answer

D. (595)

Step 1

Concept

\(S_{34}=\frac{34\times35}{2}=595\). See the last term (34) and apply the formula directly.

Step 2

Why this answer is correct

The correct answer is D. (595). \(S_{34}=\frac{34\times35}{2}=595\). See the last term (34) and apply the formula directly.

Step 3

Exam Tip

\(S_{34}=\frac{34\times35}{2}=595\) है। अंतिम पद (34) देखकर सीधे सूत्र लगाएं।

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Question 38/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 63

पहली (36) प्राकृतिक संख्याओं का योग कितना है?

What is the sum of the first (36) natural numbers?

Explanation opens after your attempt
Correct Answer

A. (666)

Step 1

Concept

\(S_{36}=\frac{36\times37}{2}=666\). Change (36) to (18) and calculate \(18\times37\).

Step 2

Why this answer is correct

The correct answer is A. (666). \(S_{36}=\frac{36\times37}{2}=666\). Change (36) to (18) and calculate \(18\times37\).

Step 3

Exam Tip

\(S_{36}=\frac{36\times37}{2}=666\) है। (36) को (18) बनाकर \(18\times37\) करें।

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Question 39/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 63

एक शिक्षक ने (1) से (31) तक रोल नंबरों का योग पूछा। सही उत्तर क्या है?

A teacher asks for the sum of roll numbers from (1) to (31). What is the correct answer?

Explanation opens after your attempt
Correct Answer

B. (496)

Step 1

Concept

\(S_{31}=\frac{31\times32}{2}=496\). If the sequence starts from (1), the last number is (n).

Step 2

Why this answer is correct

The correct answer is B. (496). \(S_{31}=\frac{31\times32}{2}=496\). If the sequence starts from (1), the last number is (n).

Step 3

Exam Tip

\(S_{31}=\frac{31\times32}{2}=496\) है। क्रम (1) से शुरू हो तो अंतिम संख्या (n) होती है।

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Question 40/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 63

पहली (45) प्राकृतिक संख्याओं का योग ज्ञात करें।

Find the sum of the first (45) natural numbers.

Explanation opens after your attempt
Correct Answer

C. (1035)

Step 1

Concept

\(S_{45}=\frac{45\times46}{2}=1035\). Change (46) to (23) and calculate \(45\times23\).

Step 2

Why this answer is correct

The correct answer is C. (1035). \(S_{45}=\frac{45\times46}{2}=1035\). Change (46) to (23) and calculate \(45\times23\).

Step 3

Exam Tip

\(S_{45}=\frac{45\times46}{2}=1035\) है। (46) को (23) बनाकर \(45\times23\) करें।

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Question 41/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 63

यदि पहली (n) प्राकृतिक संख्याओं का योग (325) है तो (n) क्या होगा?

If the sum of the first (n) natural numbers is (325), what will (n) be?

Explanation opens after your attempt
Correct Answer

C. (25)

Step 1

Concept

\(S_{25}=\frac{25\times26}{2}=325\), so (n=25). Match the given sum with the formula.

Step 2

Why this answer is correct

The correct answer is C. (25). \(S_{25}=\frac{25\times26}{2}=325\), so (n=25). Match the given sum with the formula.

Step 3

Exam Tip

\(S_{25}=\frac{25\times26}{2}=325\) इसलिए (n=25)। दिए गए योग को सूत्र से मिलाकर देखें।

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Question 42/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 63

\(1+2+3+\cdots+27\) का मान क्या है?

What is the value of \(1+2+3+\cdots+27\)?

Explanation opens after your attempt
Correct Answer

C. (378)

Step 1

Concept

\(S_{27}=\frac{27\times28}{2}=378\). Change (28) to (14) first.

Step 2

Why this answer is correct

The correct answer is C. (378). \(S_{27}=\frac{27\times28}{2}=378\). Change (28) to (14) first.

Step 3

Exam Tip

\(S_{27}=\frac{27\times28}{2}=378\) है। (28) को पहले (14) में बदलें।

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Question 43/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 63

पहली (33) प्राकृतिक संख्याओं के योग के लिए सही विकल्प चुनिए।

Choose the correct option for the sum of the first (33) natural numbers.

Explanation opens after your attempt
Correct Answer

B. (561)

Step 1

Concept

\(S_{33}=\frac{33\times34}{2}=561\). Take half of (34) as (17) and multiply.

Step 2

Why this answer is correct

The correct answer is B. (561). \(S_{33}=\frac{33\times34}{2}=561\). Take half of (34) as (17) and multiply.

Step 3

Exam Tip

\(S_{33}=\frac{33\times34}{2}=561\) है। (34) का आधा (17) लेकर गुणा करें।

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Question 44/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 63

एक पैटर्न में (1) सितारा, फिर (2) सितारे, इसी तरह (18) सितारों तक पंक्तियाँ हैं। कुल सितारे कितने हैं?

A pattern has rows with (1) star, then (2) stars, and so on up to (18) stars. How many stars are there in total?

Explanation opens after your attempt
Correct Answer

C. (171)

Step 1

Concept

Total stars are \(S_{18}=\frac{18\times19}{2}=171\). Increasing row counts form the sum of natural numbers.

Step 2

Why this answer is correct

The correct answer is C. (171). Total stars are \(S_{18}=\frac{18\times19}{2}=171\). Increasing row counts form the sum of natural numbers.

Step 3

Exam Tip

कुल सितारे \(S_{18}=\frac{18\times19}{2}=171\) हैं। पंक्ति संख्या बढ़ने पर प्राकृतिक संख्याओं का योग बनता है।

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Question 45/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 63

यदि \(S_n=465\) है तो पहली (n) प्राकृतिक संख्याओं में (n) का मान क्या है?

If \(S_n=465\), what is the value of (n) for the first (n) natural numbers?

Explanation opens after your attempt
Correct Answer

C. (30)

Step 1

Concept

\(S_{30}=\frac{30\times31}{2}=465\), so (n=30). Substituting options in the formula can give a quick answer.

Step 2

Why this answer is correct

The correct answer is C. (30). \(S_{30}=\frac{30\times31}{2}=465\), so (n=30). Substituting options in the formula can give a quick answer.

Step 3

Exam Tip

\(S_{30}=\frac{30\times31}{2}=465\) इसलिए (n=30)। विकल्पों को सूत्र में रखकर जल्दी उत्तर मिल सकता है।

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Question 46/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 63

पहली (100) प्राकृतिक संख्याओं का योग कितना है?

What is the sum of the first (100) natural numbers?

Explanation opens after your attempt
Correct Answer

B. (5050)

Step 1

Concept

\(S_{100}=\frac{100\times101}{2}=5050\). Remembering the sum up to (100) is also useful.

Step 2

Why this answer is correct

The correct answer is B. (5050). \(S_{100}=\frac{100\times101}{2}=5050\). Remembering the sum up to (100) is also useful.

Step 3

Exam Tip

\(S_{100}=\frac{100\times101}{2}=5050\) है। (100) तक के योग का मान याद रखना भी उपयोगी है।

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Question 47/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 63

पहली (37) प्राकृतिक संख्याओं का योग कितना है?

What is the sum of the first (37) natural numbers?

Explanation opens after your attempt
Correct Answer

B. (703)

Step 1

Concept

\(S_{37}=\frac{37\times38}{2}=703\). For odd (n), halve the next even factor.

Step 2

Why this answer is correct

The correct answer is B. (703). \(S_{37}=\frac{37\times38}{2}=703\). For odd (n), halve the next even factor.

Step 3

Exam Tip

\(S_{37}=\frac{37\times38}{2}=703\) है। विषम (n) में अगले सम गुणक को आधा करें।

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Question 48/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 63

\(1+2+3+\cdots+42\) का सही योग चुनिए।

Choose the correct sum of \(1+2+3+\cdots+42\).

Explanation opens after your attempt
Correct Answer

A. (903)

Step 1

Concept

\(S_{42}=\frac{42\times43}{2}=903\). Divide the even (n) by (2) to make calculation easier.

Step 2

Why this answer is correct

The correct answer is A. (903). \(S_{42}=\frac{42\times43}{2}=903\). Divide the even (n) by (2) to make calculation easier.

Step 3

Exam Tip

\(S_{42}=\frac{42\times43}{2}=903\) होता है। सम (n) को (2) से भाग देकर गणना आसान करें।

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Question 49/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 63

यदि पहली (n) प्राकृतिक संख्याओं का योग (861) है तो (n) का मान क्या है?

If the sum of the first (n) natural numbers is (861), what is the value of (n)?

Explanation opens after your attempt
Correct Answer

C. (41)

Step 1

Concept

\(S_{41}=\frac{41\times42}{2}=861\), so (n=41). In such questions, check the options in the formula.

Step 2

Why this answer is correct

The correct answer is C. (41). \(S_{41}=\frac{41\times42}{2}=861\), so (n=41). In such questions, check the options in the formula.

Step 3

Exam Tip

\(S_{41}=\frac{41\times42}{2}=861\) इसलिए (n=41)। ऐसे प्रश्नों में विकल्पों को सूत्र में रखकर जांचें।

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Question 50/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 63

एक स्कूल में (1) से (38) तक बैज नंबर बांटे गए। सभी बैज नंबरों का योग कितना होगा?

In a school, badge numbers from (1) to (38) are given. What will be the sum of all badge numbers?

Explanation opens after your attempt
Correct Answer

B. (741)

Step 1

Concept

The sum of all badge numbers is \(S_{38}=\frac{38\times39}{2}=741\). When counting starts from (1), take the last number as (n).

Step 2

Why this answer is correct

The correct answer is B. (741). The sum of all badge numbers is \(S_{38}=\frac{38\times39}{2}=741\). When counting starts from (1), take the last number as (n).

Step 3

Exam Tip

सभी बैज नंबरों का योग \(S_{38}=\frac{38\times39}{2}=741\) है। लगातार (1) से शुरू होने पर अंतिम संख्या को (n) मानें।

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