60.
If 20 men can build a wall 66 metres long in 6 days, what length of a similar
can be built by 86 men in 8 days?
Answer:
Let the required length be x metres
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.
