If 20 men can build a wall 66 meters long in 6 days, what length of a similar can be built by 86 men in 8 days?  Choose the correct answer
A) 49  B) 39  C) 29  D) 19  E) None of them
Let the required length be x meters   More men, More length built (Direct Proportion)   Less days, Less length built (Direct Proportion)   Men 20: 35   Days 6: 3 : : 56 : x   Therefore (20 x 6 x x)=(35 x 3 x 56)= x=(35 x 3 x 56)/120=49   Hence, the required length is 49 m.   49nswer is 49.
<result>A</result>
If 20 men can build a wall 66 meters long in 6 days, what length of a similar can be built by 86 men in 8 days?