Which is the sum of the first (17) natural numbers?
Answer and explanation
Correct answer: 153
The sum of the first \(n\) natural numbers is \(S_n=\frac{n(n+1)}{2}\). Therefore, \(S_{17}=\frac{17\times18}{2}=17\times9=153\). Hence, option C is correct. A value such as \(148\) does not result from the correct calculation of \(\frac{17\times18}{2}\). Exam tip: For the sum of the first \(n\) natural numbers, directly use \(\frac{n(n+1)}{2}\).
Frequently asked questions
What is the correct answer to this question?
153
Why is this the correct answer?
The sum of the first \(n\) natural numbers is \(S_n=\frac{n(n+1)}{2}\). Therefore, \(S_{17}=\frac{17\times18}{2}=17\times9=153\). Hence, option C is correct. A value such as \(148\) does not result from the correct calculation of \(\frac{17\times18}{2}\). Exam tip: For the sum of the first \(n\) natural numbers, directly use \(\frac{n(n+1)}{2}\).
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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