If 20 men can build a wall 112 metres long in 6 days, what length of a similar wall can be built by 30 men in 3 days?  Choices
A) 65mtr.
B) 84mtr
C) 70mtr.
D) 78mtr.
E) 17mtr.
20 men is 6 days can build 112 metres   30 men in 3 days can build = 112*(30/20)x(3/6)   = 84 meters   Answer: 84mtr.
<result>B</result>
If 20 men can build a wall 112 metres long in 6 days, what length of a similar wall can be built by 30 men in 3 days?