A student was asked to find the sum of first 20 odd numbers. His answer was 400. Correct?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. Yes.
The sum of the first n odd numbers is:
1 + 3 + 5 + ⋯ + (2n−1) = n2
Here, n = 20
So, 202 = 400
Hence, the student's answer is correct. The sum of the first 20 odd numbers is 400.