Problem Solving - 29

IF s is the product of integers from 100 to 200, inclusive, and t is the product of integers from 100 to 201, inclusive, what is 1/s + 1/t in terms of t?

A. (201) ^2 / t
B. [(202) (201)]/t
C. 201/t
D. 202/t
E. [(202) (201)]/(t^2)

Answer: D

Given s = 100 * ... * 200
Given t = 100 * ... * 200 * 201
=> s = t/201
Hence 1/s + 1/t = 201/t + 1/t = 202/t