Question

If 12 men and 16 boys can do a piece of work in 5 days and 13 men
and 24 boys can do it in 4 days, how long will 7 men and 10 boys take
to do it?​

Answer 1

ANSWER:

5(12 M + 16 B) = 4(13 M + 24 B)

60M + 80B = 52M + 96B

That gives, 8M = 16B, which is , 1M=2B

Now, 12 M + 16B can do work in 5 days.

So, 12 M + 8 M can do work in 5 days.

So, 20M can do work in 5 days.

Now, 7M + 10B = 7M + 5M = 12 M

Hence, if 20M can do work in 5 days, 12M can do work in (20*5)/12 = 8.33 days.