10 men or 20 boys can finish a piece of work in 15 days. How many boys are required in place of 8 men to complete the same work?
Answer & explanation
Correct answer: option 3
10M 0r 20B can complete a work in 15 days i.e. same amount of work is done by 10M as done by 20B in same number of days .
so ratio of efficiency M : B
2 : 1
that means 1M = 2B
8M = 8 × 2B = 16B
so 16 boys can do same work as done by 8 men