Some of 15%-intensity red paint is replaced with 25% solution of red paint such that the new paint intensity is 30%. What fraction of the original paint was replaced?
Choose the correct choice from the following answers
A) 1 / 5	B) 1 / 3	C) 1 / 2	D) 3 / 2	E) 3 / 5

Rationale: "let total paint = 1 let amount replaced = x 15 ( 1 - x ) + 25 x = 30 x = 3 / 2 answer : d"
Answer: D