A and B together have $100. If 3/10 of A's amount is equal to 1/5 of B's amount, how much amount does B have? Choose the correct choice from the following
A) $ 60	B) $ 55	C) $ 42	D) $ 31	E) $ 100

Rationale: "3 / 10 a = 1 / 5 b a = 1 / 5 * 10 / 3 b a = 2 / 3 b a / b = 2 / 3 a : b = 2 : 3 b ' s share = 100 * 3 / 5 = $ 60 answer is a"
Answer: A