What is the sum of the first (250) natural numbers?
Advertisement
Answer and explanation
Correct answer: 31375
The sum of the first \(n\) natural numbers is \(S_n=\frac{n(n+1)}{2}\). Therefore, \(S_{250}=\frac{250\times251}{2}=125\times251=31375\). Hence, option B is correct. Option A may result from using \(250\) in place of \(251\). Exam tip: when \(n\) is even, divide \(n\) by 2 first for quicker calculation.
Frequently asked questions
What is the correct answer to this question?
31375
Why is this the correct answer?
The sum of the first \(n\) natural numbers is \(S_n=\frac{n(n+1)}{2}\). Therefore, \(S_{250}=\frac{250\times251}{2}=125\times251=31375\). Hence, option B is correct. Option A may result from using \(250\) in place of \(251\). Exam tip: when \(n\) is even, divide \(n\) by 2 first for quicker calculation.
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.
Advertisement