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Mathematics Quiz - Class 9 Mathematics Exploring Algebrai...

Question 1/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 62

पहले (10) प्राकृतिक संख्याओं का योग क्या है?

What is the sum of the first (10) natural numbers?

Explanation opens after your attempt

Correct Answer

C. (55)

Step 1

Concept

Using (S_n=\frac{n(n+1)}{2}), \(S_{10}=\frac{10\cdot11}{2}=55\). In exams, put the correct value of (n).

Step 2

Why this answer is correct

The correct answer is C. (55). Using (S_n=\frac{n(n+1)}{2}), \(S_{10}=\frac{10\cdot11}{2}=55\). In exams, put the correct value of (n).

Step 3

Exam Tip

सूत्र (S_n=\frac{n(n+1)}{2}) से \(S_{10}=\frac{10\cdot11}{2}=55\)। परीक्षा में (n) की जगह सही संख्या रखें।

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Question 2/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 62

पहले (20) प्राकृतिक संख्याओं का योग ज्ञात कीजिए।

Find the sum of the first (20) natural numbers.

Explanation opens after your attempt

Correct Answer

B. (210)

Step 1

Concept

\(S_{20}=\frac{20\cdot21}{2}=210\). Cancelling (20) by (2) first makes calculation easy.

Step 2

Why this answer is correct

The correct answer is B. (210). \(S_{20}=\frac{20\cdot21}{2}=210\). Cancelling (20) by (2) first makes calculation easy.

Step 3

Exam Tip

\(S_{20}=\frac{20\cdot21}{2}=210\)। पहले (20) को (2) से काटना गणना आसान करता है।

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Question 3/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 62

यदि (S_n=\frac{n(n+1)}{2}), तो \(S_{15}\) क्या होगा?

If (S_n=\frac{n(n+1)}{2}), what is \(S_{15}\)?

Explanation opens after your attempt

Correct Answer

D. (120)

Step 1

Concept

\(S_{15}=\frac{15\cdot16}{2}=120\). Divide (16) by (2) before multiplying.

Step 2

Why this answer is correct

The correct answer is D. (120). \(S_{15}=\frac{15\cdot16}{2}=120\). Divide (16) by (2) before multiplying.

Step 3

Exam Tip

\(S_{15}=\frac{15\cdot16}{2}=120\)। गुणा करने से पहले (16) को (2) से भाग दें।

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Question 4/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 62

\(1+2+3+\cdots+25\) का मान क्या है?

What is the value of \(1+2+3+\cdots+25\)?

Explanation opens after your attempt

Correct Answer

A. (325)

Step 1

Concept

The sum of the first (25) natural numbers is \(\frac{25\cdot26}{2}=325\). The formula saves time in long addition.

Step 2

Why this answer is correct

The correct answer is A. (325). The sum of the first (25) natural numbers is \(\frac{25\cdot26}{2}=325\). The formula saves time in long addition.

Step 3

Exam Tip

पहले (25) प्राकृतिक संख्याओं का योग \(\frac{25\cdot26}{2}=325\) है। लंबे जोड़ में सूत्र समय बचाता है।

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Question 5/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 62

पहले (30) प्राकृतिक संख्याओं का योग कौन सा है?

Which is the sum of the first (30) natural numbers?

Explanation opens after your attempt

Correct Answer

D. (465)

Step 1

Concept

\(S_{30}=\frac{30\cdot31}{2}=465\). Dividing (30) by (2) first gives \(15\cdot31\).

Step 2

Why this answer is correct

The correct answer is D. (465). \(S_{30}=\frac{30\cdot31}{2}=465\). Dividing (30) by (2) first gives \(15\cdot31\).

Step 3

Exam Tip

\(S_{30}=\frac{30\cdot31}{2}=465\)। (30) को पहले (2) से भाग देने पर \(15\cdot31\) मिलता है।

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Question 6/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 62

पहले (12) प्राकृतिक संख्याओं का योग कितना है?

How much is the sum of the first (12) natural numbers?

Explanation opens after your attempt

Correct Answer

B. (78)

Step 1

Concept

\(S_{12}=\frac{12\cdot13}{2}=78\). Put (n=12) directly in the formula.

Step 2

Why this answer is correct

The correct answer is B. (78). \(S_{12}=\frac{12\cdot13}{2}=78\). Put (n=12) directly in the formula.

Step 3

Exam Tip

\(S_{12}=\frac{12\cdot13}{2}=78\)। सूत्र में (n=12) सीधे रखें।

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Question 7/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 62

यदि पहले (n) प्राकृतिक संख्याओं का योग निकालना हो, तो सही सूत्र कौन सा है?

Which is the correct formula for the sum of the first (n) natural numbers?

Explanation opens after your attempt

Correct Answer

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

Step 1

Concept

The sum of the first (n) natural numbers is (\frac{n(n+1)}{2}). Remembering this formula is the main key for this chapter.

Step 2

Why this answer is correct

The correct answer is C. (\frac{n(n+1)}{2}). The sum of the first (n) natural numbers is (\frac{n(n+1)}{2}). Remembering this formula is the main key for this chapter.

Step 3

Exam Tip

पहले (n) प्राकृतिक संख्याओं का योग (\frac{n(n+1)}{2}) होता है। सूत्र याद रखना इस अध्याय की मुख्य कुंजी है।

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Question 8/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 62

\(1+2+3+\cdots+50\) का योग क्या है?

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

Explanation opens after your attempt

Correct Answer

B. (1275)

Step 1

Concept

\(S_{50}=\frac{50\cdot51}{2}=1275\). Halve (50) first and then multiply by (51).

Step 2

Why this answer is correct

The correct answer is B. (1275). \(S_{50}=\frac{50\cdot51}{2}=1275\). Halve (50) first and then multiply by (51).

Step 3

Exam Tip

\(S_{50}=\frac{50\cdot51}{2}=1275\)। पहले (50) को आधा करें फिर (51) से गुणा करें।

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Question 9/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 62

पहले (5) प्राकृतिक संख्याओं का योग ज्ञात कीजिए।

Find 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). For small (n), you can also check by direct addition.

Step 2

Why this answer is correct

The correct answer is C. (15). (1+2+3+4+5=15). For small (n), you can also check by direct addition.

Step 3

Exam Tip

(1+2+3+4+5=15)। छोटे (n) के लिए सीधे जोड़कर भी जांच सकते हैं।

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Question 10/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 62

पहले (8) प्राकृतिक संख्याओं का योग क्या होगा?

What will be the sum of the first (8) natural numbers?

Explanation opens after your attempt

Correct Answer

A. (36)

Step 1

Concept

\(S_8=\frac{8\cdot9}{2}=36\). Divide (8) by (2) and calculate \(4\cdot9\).

Step 2

Why this answer is correct

The correct answer is A. (36). \(S_8=\frac{8\cdot9}{2}=36\). Divide (8) by (2) and calculate \(4\cdot9\).

Step 3

Exam Tip

\(S_8=\frac{8\cdot9}{2}=36\)। (8) को (2) से भाग देकर \(4\cdot9\) करें।

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Question 11/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 62

पहले (18) प्राकृतिक संख्याओं का योग कौन सा है?

Which is the sum of the first (18) natural numbers?

Explanation opens after your attempt

Correct Answer

B. (171)

Step 1

Concept

\(S_{18}=\frac{18\cdot19}{2}=171\). It is easy to write it as \(9\cdot19\).

Step 2

Why this answer is correct

The correct answer is B. (171). \(S_{18}=\frac{18\cdot19}{2}=171\). It is easy to write it as \(9\cdot19\).

Step 3

Exam Tip

\(S_{18}=\frac{18\cdot19}{2}=171\)। आधा करके \(9\cdot19\) लिखना आसान है।

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Question 12/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 62

यदि पहले (n) प्राकृतिक संख्याओं का योग (120) है, तो (n) क्या है?

If the sum of the first (n) natural numbers is (120), what is (n)?

Explanation opens after your attempt

Correct Answer

C. (15)

Step 1

Concept

\(\frac{15\cdot16}{2}=120\), so (n=15). In such questions, test the options in the formula.

Step 2

Why this answer is correct

The correct answer is C. (15). \(\frac{15\cdot16}{2}=120\), so (n=15). In such questions, test the options in the formula.

Step 3

Exam Tip

\(\frac{15\cdot16}{2}=120\), इसलिए (n=15)। ऐसे प्रश्नों में विकल्पों को सूत्र में रखकर जांचें।

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Question 13/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 62

पहले (40) प्राकृतिक संख्याओं का योग कितना है?

How much is the sum of the first (40) natural numbers?

Explanation opens after your attempt

Correct Answer

C. (820)

Step 1

Concept

\(S_{40}=\frac{40\cdot41}{2}=820\). Take half of (40) as (20) and calculate \(20\cdot41\).

Step 2

Why this answer is correct

The correct answer is C. (820). \(S_{40}=\frac{40\cdot41}{2}=820\). Take half of (40) as (20) and calculate \(20\cdot41\).

Step 3

Exam Tip

\(S_{40}=\frac{40\cdot41}{2}=820\)। (40) का आधा (20) लेकर \(20\cdot41\) करें।

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Question 14/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 62

\(1+2+3+\cdots+100\) का मान क्या होगा?

What will be the value of \(1+2+3+\cdots+100\)?

Explanation opens after your attempt

Correct Answer

B. (5050)

Step 1

Concept

\(S_{100}=\frac{100\cdot101}{2}=5050\). Use the formula directly for large sums.

Step 2

Why this answer is correct

The correct answer is B. (5050). \(S_{100}=\frac{100\cdot101}{2}=5050\). Use the formula directly for large sums.

Step 3

Exam Tip

\(S_{100}=\frac{100\cdot101}{2}=5050\)। बड़े योग में सूत्र सीधे उपयोग करें।

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Question 15/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 62

पहले (7) प्राकृतिक संख्याओं का योग क्या है?

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

Explanation opens after your attempt

Correct Answer

D. (28)

Step 1

Concept

\(S_7=\frac{7\cdot8}{2}=28\). For odd (n), divide the next even number by (2) first.

Step 2

Why this answer is correct

The correct answer is D. (28). \(S_7=\frac{7\cdot8}{2}=28\). For odd (n), divide the next even number by (2) first.

Step 3

Exam Tip

\(S_7=\frac{7\cdot8}{2}=28\)। विषम (n) में अगले सम संख्या को पहले (2) से भाग दें।

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Question 16/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 62

पहले (9) प्राकृतिक संख्याओं का योग ज्ञात कीजिए।

Find the sum of the first (9) natural numbers.

Explanation opens after your attempt

Correct Answer

A. (45)

Step 1

Concept

\(S_9=\frac{9\cdot10}{2}=45\). Divide (10) by (2) and calculate \(9\cdot5\).

Step 2

Why this answer is correct

The correct answer is A. (45). \(S_9=\frac{9\cdot10}{2}=45\). Divide (10) by (2) and calculate \(9\cdot5\).

Step 3

Exam Tip

\(S_9=\frac{9\cdot10}{2}=45\)। (10) को (2) से भाग देकर \(9\cdot5\) करें।

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Question 17/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 62

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

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

Explanation opens after your attempt

Correct Answer

B. (21)

Step 1

Concept

\(S_6=\frac{6\cdot7}{2}=21\). Put (n=6) correctly in the formula.

Step 2

Why this answer is correct

The correct answer is B. (21). \(S_6=\frac{6\cdot7}{2}=21\). Put (n=6) correctly in the formula.

Step 3

Exam Tip

\(S_6=\frac{6\cdot7}{2}=21\)। सूत्र में (n=6) सही ढंग से रखें।

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Question 18/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 62

पहले (14) प्राकृतिक संख्याओं का योग कितना होगा?

How much will be the sum of the first (14) natural numbers?

Explanation opens after your attempt

Correct Answer

C. (105)

Step 1

Concept

\(S_{14}=\frac{14\cdot15}{2}=105\). Divide (14) by (2) first and calculate \(7\cdot15\).

Step 2

Why this answer is correct

The correct answer is C. (105). \(S_{14}=\frac{14\cdot15}{2}=105\). Divide (14) by (2) first and calculate \(7\cdot15\).

Step 3

Exam Tip

\(S_{14}=\frac{14\cdot15}{2}=105\)। पहले (14) को (2) से भाग देकर \(7\cdot15\) करें।

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Question 19/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 62

पहले (11) प्राकृतिक संख्याओं का योग क्या है?

What is the sum of the first (11) natural numbers?

Explanation opens after your attempt

Correct Answer

B. (66)

Step 1

Concept

\(S_{11}=\frac{11\cdot12}{2}=66\). Take half of (12) as (6) and calculate \(11\cdot6\).

Step 2

Why this answer is correct

The correct answer is B. (66). \(S_{11}=\frac{11\cdot12}{2}=66\). Take half of (12) as (6) and calculate \(11\cdot6\).

Step 3

Exam Tip

\(S_{11}=\frac{11\cdot12}{2}=66\)। (12) का आधा (6) लेकर \(11\cdot6\) करें।

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Question 20/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 62

यदि पहले (n) प्राकृतिक संख्याओं का योग (55) है, तो (n) क्या होगा?

If the sum of the first (n) natural numbers is (55), what will (n) be?

Explanation opens after your attempt

Correct Answer

C. (10)

Step 1

Concept

\(\frac{10\cdot11}{2}=55\), so (n=10). Testing options quickly is an easy method.

Step 2

Why this answer is correct

The correct answer is C. (10). \(\frac{10\cdot11}{2}=55\), so (n=10). Testing options quickly is an easy method.

Step 3

Exam Tip

\(\frac{10\cdot11}{2}=55\), इसलिए (n=10)। विकल्पों को जल्दी जांचना आसान तरीका है।

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Question 21/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 62

पहले (16) प्राकृतिक संख्याओं का योग कौन सा है?

Which is the sum of the first (16) natural numbers?

Explanation opens after your attempt

Correct Answer

D. (136)

Step 1

Concept

\(S_{16}=\frac{16\cdot17}{2}=136\). Halve (16) and calculate \(8\cdot17\).

Step 2

Why this answer is correct

The correct answer is D. (136). \(S_{16}=\frac{16\cdot17}{2}=136\). Halve (16) and calculate \(8\cdot17\).

Step 3

Exam Tip

\(S_{16}=\frac{16\cdot17}{2}=136\)। (16) को आधा करके \(8\cdot17\) करें।

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Question 22/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 62

किसका योग \(1+2+3+\cdots+n\) के लिए सही लिखा गया है?

Which is correctly written for the sum \(1+2+3+\cdots+n\)?

Explanation opens after your attempt

Correct Answer

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

Step 1

Concept

(1+2+3+\cdots+n=\frac{n(n+1)}{2}). This basic formula is useful in every question.

Step 2

Why this answer is correct

The correct answer is B. (\frac{n(n+1)}{2}). (1+2+3+\cdots+n=\frac{n(n+1)}{2}). This basic formula is useful in every question.

Step 3

Exam Tip

(1+2+3+\cdots+n=\frac{n(n+1)}{2}) होता है। यह मूल सूत्र हर प्रश्न में काम आता है।

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Question 23/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 62

पहले (13) प्राकृतिक संख्याओं का योग ज्ञात कीजिए।

Find the sum of the first (13) natural numbers.

Explanation opens after your attempt

Correct Answer

C. (91)

Step 1

Concept

\(S_{13}=\frac{13\cdot14}{2}=91\). Take half of (14) as (7) and calculate \(13\cdot7\).

Step 2

Why this answer is correct

The correct answer is C. (91). \(S_{13}=\frac{13\cdot14}{2}=91\). Take half of (14) as (7) and calculate \(13\cdot7\).

Step 3

Exam Tip

\(S_{13}=\frac{13\cdot14}{2}=91\)। (14) का आधा (7) लेकर \(13\cdot7\) करें।

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Question 24/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 62

पहले (4) प्राकृतिक संख्याओं का योग कितना है?

How much is the sum of the first (4) natural numbers?

Explanation opens after your attempt

Correct Answer

C. (10)

Step 1

Concept

(1+2+3+4=10). In small sums, you can check the answer by direct addition.

Step 2

Why this answer is correct

The correct answer is C. (10). (1+2+3+4=10). In small sums, you can check the answer by direct addition.

Step 3

Exam Tip

(1+2+3+4=10)। छोटे योग में सीधे जोड़कर उत्तर जांच सकते हैं।

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Question 25/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 62

पहले (22) प्राकृतिक संख्याओं का योग क्या होगा?

What will be the sum of the first (22) natural numbers?

Explanation opens after your attempt

Correct Answer

A. (253)

Step 1

Concept

\(S_{22}=\frac{22\cdot23}{2}=253\). Take half of (22) as (11) and calculate \(11\cdot23\).

Step 2

Why this answer is correct

The correct answer is A. (253). \(S_{22}=\frac{22\cdot23}{2}=253\). Take half of (22) as (11) and calculate \(11\cdot23\).

Step 3

Exam Tip

\(S_{22}=\frac{22\cdot23}{2}=253\)। (22) का आधा (11) लेकर \(11\cdot23\) करें।

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Question 26/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 62

यदि \(S_n=465\), तो (n) का मान क्या है?

If \(S_n=465\), what is the value of (n)?

Explanation opens after your attempt

Correct Answer

C. (30)

Step 1

Concept

\(\frac{30\cdot31}{2}=465\), so (n=30). Match the options with the formula.

Step 2

Why this answer is correct

The correct answer is C. (30). \(\frac{30\cdot31}{2}=465\), so (n=30). Match the options with the formula.

Step 3

Exam Tip

\(\frac{30\cdot31}{2}=465\), इसलिए (n=30)। विकल्पों में से सूत्र से मिलान करें।

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Question 27/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 62

पहले (24) प्राकृतिक संख्याओं का योग कितना है?

How much is the sum of the first (24) natural numbers?

Explanation opens after your attempt

Correct Answer

C. (300)

Step 1

Concept

\(S_{24}=\frac{24\cdot25}{2}=300\). First halve (24) and calculate \(12\cdot25\).

Step 2

Why this answer is correct

The correct answer is C. (300). \(S_{24}=\frac{24\cdot25}{2}=300\). First halve (24) and calculate \(12\cdot25\).

Step 3

Exam Tip

\(S_{24}=\frac{24\cdot25}{2}=300\)। पहले (24) को आधा करके \(12\cdot25\) करें।

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Question 28/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 62

पहले (3) प्राकृतिक संख्याओं का योग क्या है?

What is the sum of the first (3) natural numbers?

Explanation opens after your attempt

Correct Answer

C. (6)

Step 1

Concept

(1+2+3=6). For the first few terms, direct addition is simplest.

Step 2

Why this answer is correct

The correct answer is C. (6). (1+2+3=6). For the first few terms, direct addition is simplest.

Step 3

Exam Tip

(1+2+3=6)। शुरुआती पदों में सीधे जोड़ना सबसे सरल है।

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Question 29/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 62

पहले (60) प्राकृतिक संख्याओं का योग ज्ञात कीजिए।

Find the sum of the first (60) natural numbers.

Explanation opens after your attempt

Correct Answer

A. (1830)

Step 1

Concept

\(S_{60}=\frac{60\cdot61}{2}=1830\). Use the formula directly for large (n).

Step 2

Why this answer is correct

The correct answer is A. (1830). \(S_{60}=\frac{60\cdot61}{2}=1830\). Use the formula directly for large (n).

Step 3

Exam Tip

\(S_{60}=\frac{60\cdot61}{2}=1830\)। बड़े (n) में सूत्र सीधे उपयोग करें।

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Question 30/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 62

यदि पहले (n) प्राकृतिक संख्याओं का योग (210) है, तो (n) क्या है?

If the sum of the first (n) natural numbers is (210), what is (n)?

Explanation opens after your attempt

Correct Answer

C. (20)

Step 1

Concept

\(\frac{20\cdot21}{2}=210\), so (n=20). Put the options in the formula to find the correct (n).

Step 2

Why this answer is correct

The correct answer is C. (20). \(\frac{20\cdot21}{2}=210\), so (n=20). Put the options in the formula to find the correct (n).

Step 3

Exam Tip

\(\frac{20\cdot21}{2}=210\), इसलिए (n=20)। सही (n) के लिए विकल्पों को सूत्र में रखें।

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Question 31/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 62

पहले (17) प्राकृतिक संख्याओं का योग क्या है?

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

Explanation opens after your attempt

Correct Answer

C. (153)

Step 1

Concept

\(S_{17}=\frac{17\cdot18}{2}=153\). Divide (18) by (2) and calculate \(17\cdot9\).

Step 2

Why this answer is correct

The correct answer is C. (153). \(S_{17}=\frac{17\cdot18}{2}=153\). Divide (18) by (2) and calculate \(17\cdot9\).

Step 3

Exam Tip

\(S_{17}=\frac{17\cdot18}{2}=153\)। (18) को (2) से भाग देकर \(17\cdot9\) करें।

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Question 32/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 62

\(1+2+3+\cdots+19\) का मान क्या है?

What is the value of \(1+2+3+\cdots+19\)?

Explanation opens after your attempt

Correct Answer

B. (190)

Step 1

Concept

\(S_{19}=\frac{19\cdot20}{2}=190\). First halve (20) to get (10).

Step 2

Why this answer is correct

The correct answer is B. (190). \(S_{19}=\frac{19\cdot20}{2}=190\). First halve (20) to get (10).

Step 3

Exam Tip

\(S_{19}=\frac{19\cdot20}{2}=190\)। पहले (20) का आधा (10) करें।

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Question 33/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 62

पहले (2) प्राकृतिक संख्याओं का योग कौन सा है?

Which is the sum of the first (2) natural numbers?

Explanation opens after your attempt

Correct Answer

C. (3)

Step 1

Concept

(1+2=3). Natural numbers start from (1).

Step 2

Why this answer is correct

The correct answer is C. (3). (1+2=3). Natural numbers start from (1).

Step 3

Exam Tip

(1+2=3)। प्राकृतिक संख्याएं (1) से शुरू होती हैं।

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Question 34/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 62

पहले (26) प्राकृतिक संख्याओं का योग क्या होगा?

What will be the sum of the first (26) natural numbers?

Explanation opens after your attempt

Correct Answer

C. (351)

Step 1

Concept

\(S_{26}=\frac{26\cdot27}{2}=351\). Divide (26) by (2) and calculate \(13\cdot27\).

Step 2

Why this answer is correct

The correct answer is C. (351). \(S_{26}=\frac{26\cdot27}{2}=351\). Divide (26) by (2) and calculate \(13\cdot27\).

Step 3

Exam Tip

\(S_{26}=\frac{26\cdot27}{2}=351\)। (26) को (2) से भाग देकर \(13\cdot27\) करें।

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Question 35/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 62

यदि \(S_n=78\), तो (n) का मान क्या होगा?

If \(S_n=78\), what will be the value of (n)?

Explanation opens after your attempt

Correct Answer

C. (12)

Step 1

Concept

\(\frac{12\cdot13}{2}=78\), so (n=12). It is important to verify the answer with the formula.

Step 2

Why this answer is correct

The correct answer is C. (12). \(\frac{12\cdot13}{2}=78\), so (n=12). It is important to verify the answer with the formula.

Step 3

Exam Tip

\(\frac{12\cdot13}{2}=78\), इसलिए (n=12)। उत्तर को सूत्र से जांचना जरूरी है।

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Question 36/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 62

पहले (35) प्राकृतिक संख्याओं का योग कितना है?

How much is the sum of the first (35) natural numbers?

Explanation opens after your attempt

Correct Answer

C. (630)

Step 1

Concept

\(S_{35}=\frac{35\cdot36}{2}=630\). Halve (36) and calculate \(18\cdot35\).

Step 2

Why this answer is correct

The correct answer is C. (630). \(S_{35}=\frac{35\cdot36}{2}=630\). Halve (36) and calculate \(18\cdot35\).

Step 3

Exam Tip

\(S_{35}=\frac{35\cdot36}{2}=630\)। (36) को आधा कर \(18\cdot35\) करें।

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Question 37/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 62

एक छात्र ने (1) से (10) तक सभी प्राकृतिक संख्याएं जोड़ीं। उसे कितना योग मिलेगा?

A student added all natural numbers from (1) to (10). What sum will he get?

Explanation opens after your attempt

Correct Answer

A. (55)

Step 1

Concept

The sum from (1) to (10) is \(S_{10}=55\). In such cases, identify (n) from the last number.

Step 2

Why this answer is correct

The correct answer is A. (55). The sum from (1) to (10) is \(S_{10}=55\). In such cases, identify (n) from the last number.

Step 3

Exam Tip

(1) से (10) तक का योग \(S_{10}=55\) है। ऐसी स्थिति में पहले और अंतिम संख्या से (n) पहचानें।

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Question 38/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 62

पहले (45) प्राकृतिक संख्याओं का योग क्या है?

What is the sum of the first (45) natural numbers?

Explanation opens after your attempt

Correct Answer

B. (1035)

Step 1

Concept

\(S_{45}=\frac{45\cdot46}{2}=1035\). Take half of (46) as (23) and calculate \(45\cdot23\).

Step 2

Why this answer is correct

The correct answer is B. (1035). \(S_{45}=\frac{45\cdot46}{2}=1035\). Take half of (46) as (23) and calculate \(45\cdot23\).

Step 3

Exam Tip

\(S_{45}=\frac{45\cdot46}{2}=1035\)। (46) का आधा (23) लेकर \(45\cdot23\) करें।

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Question 39/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 62

यदि \(S_n=325\), तो (n) क्या होगा?

If \(S_n=325\), what will (n) be?

Explanation opens after your attempt

Correct Answer

C. (25)

Step 1

Concept

\(\frac{25\cdot26}{2}=325\), so (n=25). Check the options using the formula.

Step 2

Why this answer is correct

The correct answer is C. (25). \(\frac{25\cdot26}{2}=325\), so (n=25). Check the options using the formula.

Step 3

Exam Tip

\(\frac{25\cdot26}{2}=325\), इसलिए (n=25)। विकल्पों को सूत्र से जांचें।

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Question 40/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 62

पहले (28) प्राकृतिक संख्याओं का योग कितना होगा?

How much will be the sum of the first (28) natural numbers?

Explanation opens after your attempt

Correct Answer

A. (406)

Step 1

Concept

\(S_{28}=\frac{28\cdot29}{2}=406\). Take half of (28) as (14) and calculate \(14\cdot29\).

Step 2

Why this answer is correct

The correct answer is A. (406). \(S_{28}=\frac{28\cdot29}{2}=406\). Take half of (28) as (14) and calculate \(14\cdot29\).

Step 3

Exam Tip

\(S_{28}=\frac{28\cdot29}{2}=406\)। (28) का आधा (14) लेकर \(14\cdot29\) करें।

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Question 41/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 62

पहले (32) प्राकृतिक संख्याओं का योग ज्ञात कीजिए।

Find the sum of the first (32) natural numbers.

Explanation opens after your attempt

Correct Answer

C. (528)

Step 1

Concept

\(S_{32}=\frac{32\cdot33}{2}=528\). Take half of (32) as (16) and calculate \(16\cdot33\).

Step 2

Why this answer is correct

The correct answer is C. (528). \(S_{32}=\frac{32\cdot33}{2}=528\). Take half of (32) as (16) and calculate \(16\cdot33\).

Step 3

Exam Tip

\(S_{32}=\frac{32\cdot33}{2}=528\)। (32) का आधा (16) लेकर \(16\cdot33\) करें।

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Question 42/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 62

पहले (1) प्राकृतिक संख्या का योग क्या है?

What is the sum of the first (1) natural number?

Explanation opens after your attempt

Correct Answer

B. (1)

Step 1

Concept

The first natural number is (1), so the sum is (1). Natural numbers start from (1).

Step 2

Why this answer is correct

The correct answer is B. (1). The first natural number is (1), so the sum is (1). Natural numbers start from (1).

Step 3

Exam Tip

पहली प्राकृतिक संख्या (1) है, इसलिए योग (1) है। प्राकृतिक संख्याएं (1) से शुरू होती हैं।

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Question 43/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 62

\(1+2+3+\cdots+75\) का योग क्या है?

What is the sum of \(1+2+3+\cdots+75\)?

Explanation opens after your attempt

Correct Answer

C. (2850)

Step 1

Concept

\(S_{75}=\frac{75\cdot76}{2}=2850\). Take half of (76) as (38) and calculate \(75\cdot38\).

Step 2

Why this answer is correct

The correct answer is C. (2850). \(S_{75}=\frac{75\cdot76}{2}=2850\). Take half of (76) as (38) and calculate \(75\cdot38\).

Step 3

Exam Tip

\(S_{75}=\frac{75\cdot76}{2}=2850\)। (76) का आधा (38) लेकर \(75\cdot38\) करें।

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Question 44/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 62

यदि पहले (n) प्राकृतिक संख्याओं का योग (36) है, तो (n) क्या है?

If the sum of the first (n) natural numbers is (36), what is (n)?

Explanation opens after your attempt

Correct Answer

C. (8)

Step 1

Concept

\(\frac{8\cdot9}{2}=36\), so (n=8). Quickly check the option in the formula.

Step 2

Why this answer is correct

The correct answer is C. (8). \(\frac{8\cdot9}{2}=36\), so (n=8). Quickly check the option in the formula.

Step 3

Exam Tip

\(\frac{8\cdot9}{2}=36\), इसलिए (n=8)। विकल्प को सूत्र में रखकर जल्दी जांचें।

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Question 45/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 62

पहले (23) प्राकृतिक संख्याओं का योग कौन सा है?

Which is the sum of the first (23) natural numbers?

Explanation opens after your attempt

Correct Answer

B. (276)

Step 1

Concept

\(S_{23}=\frac{23\cdot24}{2}=276\). Take half of (24) as (12) and calculate \(23\cdot12\).

Step 2

Why this answer is correct

The correct answer is B. (276). \(S_{23}=\frac{23\cdot24}{2}=276\). Take half of (24) as (12) and calculate \(23\cdot12\).

Step 3

Exam Tip

\(S_{23}=\frac{23\cdot24}{2}=276\)। (24) का आधा (12) लेकर \(23\cdot12\) करें।

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Question 46/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 62

पहले (27) प्राकृतिक संख्याओं का योग क्या है?

What is the sum of the first (27) natural numbers?

Explanation opens after your attempt

Correct Answer

B. (378)

Step 1

Concept

\(S_{27}=\frac{27\cdot28}{2}=378\). Take half of (28) as (14) and calculate \(27\cdot14\).

Step 2

Why this answer is correct

The correct answer is B. (378). \(S_{27}=\frac{27\cdot28}{2}=378\). Take half of (28) as (14) and calculate \(27\cdot14\).

Step 3

Exam Tip

\(S_{27}=\frac{27\cdot28}{2}=378\)। (28) का आधा (14) लेकर \(27\cdot14\) करें।

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Question 47/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 62

एक शिक्षक ने (1) से (15) तक संख्याएं जोड़ने को कहा। सही योग क्या है?

A teacher asked to add numbers from (1) to (15). What is the correct sum?

Explanation opens after your attempt

Correct Answer

C. (120)

Step 1

Concept

The sum from (1) to (15) is \(S_{15}=120\). The last number is (n).

Step 2

Why this answer is correct

The correct answer is C. (120). The sum from (1) to (15) is \(S_{15}=120\). The last number is (n).

Step 3

Exam Tip

(1) से (15) तक का योग \(S_{15}=120\) है। अंतिम संख्या ही (n) होती है।

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Question 48/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 62

पहले (55) प्राकृतिक संख्याओं का योग कितना है?

How much is the sum of the first (55) natural numbers?

Explanation opens after your attempt

Correct Answer

A. (1540)

Step 1

Concept

\(S_{55}=\frac{55\cdot56}{2}=1540\). Take half of (56) as (28) and calculate \(55\cdot28\).

Step 2

Why this answer is correct

The correct answer is A. (1540). \(S_{55}=\frac{55\cdot56}{2}=1540\). Take half of (56) as (28) and calculate \(55\cdot28\).

Step 3

Exam Tip

\(S_{55}=\frac{55\cdot56}{2}=1540\)। (56) का आधा (28) लेकर \(55\cdot28\) करें।

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Question 49/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 62

यदि \(S_n=91\), तो (n) का सही मान क्या है?

If \(S_n=91\), what is the correct value of (n)?

Explanation opens after your attempt

Correct Answer

C. (13)

Step 1

Concept

\(\frac{13\cdot14}{2}=91\), so (n=13). Always verify the answer with the formula.

Step 2

Why this answer is correct

The correct answer is C. (13). \(\frac{13\cdot14}{2}=91\), so (n=13). Always verify the answer with the formula.

Step 3

Exam Tip

\(\frac{13\cdot14}{2}=91\), इसलिए (n=13)। उत्तर को सूत्र से अवश्य सत्यापित करें।

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Question 50/50 Easy Mathematics Sequences and Progressions Sum of first n natural numbers Class 9 Level 62

पहले (36) प्राकृतिक संख्याओं का योग क्या होगा?

What will be the sum of the first (36) natural numbers?

Explanation opens after your attempt

Correct Answer

C. (666)

Step 1

Concept

\(S_{36}=\frac{36\cdot37}{2}=666\). Halve (36) and calculate \(18\cdot37\).

Step 2

Why this answer is correct

The correct answer is C. (666). \(S_{36}=\frac{36\cdot37}{2}=666\). Halve (36) and calculate \(18\cdot37\).

Step 3

Exam Tip

\(S_{36}=\frac{36\cdot37}{2}=666\)। (36) को आधा कर \(18\cdot37\) करें।

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Class 9 Mathematics - Exploring Algebraic Identities - Visual models of identities Easy Quiz

पहले (10) प्राकृतिक संख्याओं का योग क्या है?

Concept

Why this answer is correct

Exam Tip

पहले (20) प्राकृतिक संख्याओं का योग ज्ञात कीजिए।

Concept

Why this answer is correct

Exam Tip

यदि (S_n=\frac{n(n+1)}{2}), तो \(S_{15}\) क्या होगा?

Concept

Why this answer is correct

Exam Tip

\(1+2+3+\cdots+25\) का मान क्या है?

Concept

Why this answer is correct

Exam Tip

पहले (30) प्राकृतिक संख्याओं का योग कौन सा है?

Concept

Why this answer is correct

Exam Tip

पहले (12) प्राकृतिक संख्याओं का योग कितना है?

Concept

Why this answer is correct

Exam Tip

यदि पहले (n) प्राकृतिक संख्याओं का योग निकालना हो, तो सही सूत्र कौन सा है?

Concept

Why this answer is correct

Exam Tip

\(1+2+3+\cdots+50\) का योग क्या है?

Concept

Why this answer is correct

Exam Tip

पहले (5) प्राकृतिक संख्याओं का योग ज्ञात कीजिए।

Concept

Why this answer is correct

Exam Tip

पहले (8) प्राकृतिक संख्याओं का योग क्या होगा?

Concept

Why this answer is correct

Exam Tip

पहले (18) प्राकृतिक संख्याओं का योग कौन सा है?

Concept

Why this answer is correct

Exam Tip

यदि पहले (n) प्राकृतिक संख्याओं का योग (120) है, तो (n) क्या है?

Concept

Why this answer is correct

Exam Tip

पहले (40) प्राकृतिक संख्याओं का योग कितना है?

Concept

Why this answer is correct

Exam Tip

\(1+2+3+\cdots+100\) का मान क्या होगा?

Concept

Why this answer is correct

Exam Tip

पहले (7) प्राकृतिक संख्याओं का योग क्या है?

Concept

Why this answer is correct

Exam Tip

पहले (9) प्राकृतिक संख्याओं का योग ज्ञात कीजिए।

Concept

Why this answer is correct

Exam Tip

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

Concept

Why this answer is correct

Exam Tip

पहले (14) प्राकृतिक संख्याओं का योग कितना होगा?

Concept

Why this answer is correct

Exam Tip

पहले (11) प्राकृतिक संख्याओं का योग क्या है?

Concept

Why this answer is correct

Exam Tip

यदि पहले (n) प्राकृतिक संख्याओं का योग (55) है, तो (n) क्या होगा?

Concept

Why this answer is correct