Question

After inserting n AMs between 2 and 38, the sum of the resulting progression is 200. The value of n is

(A)  10 

(B)  8 

(C)  9 

(D)  None of these

Answer 1

Correct option (B) 8

The resulting progression will have n + 2 terms with 2 as the first term and 38 as the last term. Therefore, the sum of the progression

(n + 2)/2(2 + 38) = 20(n + 2)

By hypothesis, 20(n + 2) = 200 ⇒ n = 8