What will be the sum of the first (22) natural numbers?
Answer and explanation
Correct answer: 253
The sum of the first \(n\) natural numbers is \(S_n=\frac{n(n+1)}{2}\). Therefore, \(S_{22}=\frac{22\times23}{2}=11\times23=253\). The option 242 may result from calculating \(22\times11\), but the correct formula must include \(n+1=23\). Exam tip: Use \(\frac{n(n+1)}{2}\) and divide the even factor by 2 before multiplying.
Frequently asked questions
What is the correct answer to this question?
253
Why is this the correct answer?
The sum of the first \(n\) natural numbers is \(S_n=\frac{n(n+1)}{2}\). Therefore, \(S_{22}=\frac{22\times23}{2}=11\times23=253\). The option 242 may result from calculating \(22\times11\), but the correct formula must include \(n+1=23\). Exam tip: Use \(\frac{n(n+1)}{2}\) and divide the even factor by 2 before multiplying.
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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