Drum X is 1/2 full of oil and drum Y, which has twice the capacity of drum X, is 2/5 full of oil. If all of the oil in drum X is poured into drum Y, then drum Y will be filled to what capacity?
Select:
A) 4 / 5	B) 8 / 15	C) 11 / 15	D) 9 / 20	E) 13 / 20

Rationale: "( 1 / 2 ) x = ( 1 / 4 ) y ( 1 / 4 ) y + ( 2 / 5 ) y = ( 13 / 20 ) y the answer is e ."
Answer: E