Welcome to the LEAP Q&A Forum

Find your questions answered. Here.

GRE - Quantitative Reasoning - Number Theory

For each integer n > 1, let A(n) denote the sum of the integers from 1 to n. For example, A(100) = 1 + 2 + 3 + … + 100 = 5,050. What is the value of A(200)?

For each integer n > 1, let A(n) denote the sum of the integers from 1 to n. For example, A(100) = 1 2 3 … 100 = 5,050. What is the value of A(200)?

A. 10,100
B. 15,050
C. 15,150
D. 20,100
E. 21,500

A(200) = 1 + 2 + . . . + 200

Sum of consecutive numbers starting from 1 = n(n+1)/2 = 200*201/ 2 = 20100

D is correct