If 15 men can build a wall of forty two metres long in 5 days, what length of a similar wall can be built by 25 men in 4 days	Choose the correct choice from the following options:  A) 48 metres  B) 56 metres  C) 60 metres  D) 62 metres  E) None of these
Explanation :   Solution: Let the required length be x metres.   More men, more length built (Direct proportion)   Less days, less length built (Direct proportion)   men 15 : 25   days 5 : 4   .'.(15*5*x) = (25*4*42)   x = 56 metres.   Answer : 56 metres
<result>B</result>
If 15 men can build a wall of forty two metres long in 5 days, what length of a similar wall can be built by 25 men in 4 days