Question

The sum of the first 100 positive integers is 5,050. What is the sum of the first 200 positive integers?

A. 10,000B. 10,200C. 15,050D. 20,050E. 20,100

Answer 1

The sum of the k for k=1 to k="n"=(n*(n+1))/2 , where "n" is the total integer.

In this problem n = 200

Sum = (200*201)/2 = 20,100