Discussion Forum

If 36 men can do a piece of work in 25 hours, in how many hours will 15 men do it ?

Answer:

Explanation:

Let the required number of hours be $x$. Then,

Less men, More hours (Indirect Proportion)

$\therefore 15:36 :: 25:x$

$(15\times x)=(36\times 25)$   

$\Leftrightarrow x=\frac{36\times 25}{15}$ $= 60$.

Hence, 15 men can do it in 60 hours.