If 20 men can build a wall 112 metres long in 6 days, what length of a similar wall can be built by 15 men in 3 days? Choose the correct choice from the following answers.
A) 65 mtr .	B) 52 mtr	C) 70 mtr .	D) 78 mtr .	E) 42 mtr .

Rationale: "20 men is 6 days can build 112 metres 15 men in 3 days can build = 112 * ( 15 / 20 ) x ( 3 / 6 ) = 42 meters answer : e ."
Answer: E