12 men and 18 boys, working \(7\frac{1}{2}\) hours a day, can do a piece if work in 60 days. If a man works in 50 days, working 9 hours a day ?

A 40

B 50

C 42

D 26

Correct Answer: Option C

Solution: So twice the work requires twice the boys

total boys require = 42 \( \times \) 2 = 84

Now, 21 men can work 21 \( \times \) 2 = 42 boys

So, number of boys to help 21 men is 84 - 42 = 42