What is the sum of the first (17) natural numbers?
Answer and explanation
Correct answer: 153
The sum of the first \(n\) natural numbers is \(\frac{n(n+1)}{2}\). Substituting \(n=17\), we get \(\frac{17\times18}{2}=17\times9=153\), so 153 is correct. The value 170 may result from using \(17\times10\), but that is not the correct sum formula. Exam tip: for the sum of the first \(n\) natural numbers, 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 \(\frac{n(n+1)}{2}\). Substituting \(n=17\), we get \(\frac{17\times18}{2}=17\times9=153\), so 153 is correct. The value 170 may result from using \(17\times10\), but that is not the correct sum formula. Exam tip: for the sum of the first \(n\) natural numbers, 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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