Which is the sum of the first (23) natural numbers?
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Answer and explanation
Correct answer: 276
The sum of the first \(n\) natural numbers is \(S_n=\frac{n(n+1)}{2}\). Therefore, \(S_{23}=\frac{23\times24}{2}=23\times12=276\). Hence, option B is correct. \(264\) may result from incorrectly halving 24. Exam tip: do not forget to use \(n+1\) in the formula.
Frequently asked questions
What is the correct answer to this question?
276
Why is this the correct answer?
The sum of the first \(n\) natural numbers is \(S_n=\frac{n(n+1)}{2}\). Therefore, \(S_{23}=\frac{23\times24}{2}=23\times12=276\). Hence, option B is correct. \(264\) may result from incorrectly halving 24. Exam tip: do not forget to use \(n+1\) in the formula.
Which subject and chapter does this question cover?
This is a Class 9 Mathematics question. Chapter: Sequences and Progressions. Topic: Sum of first n natural numbers.
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