At a loading dock, each worker on the night crew loaded 1/4 as many boxes as each worker on the day crew. If the night crew has 4/5 as many workers as the day crew, what fraction of all the boxes loaded by the two crews did the day crew load? Choose the most appropriate option
A) 1 / 2	B) 2 / 5	C) 3 / 5	D) 4 / 5	E) 5 / 6

Rationale: "method : x = no . of boxes loaded by day crew . boxes by night crew = 1 / 4 * 4 / 5 x = 1 / 5 x % loaded by day crew = x / ( x + 1 / 5 x ) = 5 / 6 answer e"
Answer: E