In power plant, If 36 men can do a piece of work in 25 hours, in how many hours will 15 men do it ?  Choose the correct choice from the following answers.
A) 40 hours  B) 50 hours  C) 60 hours  D) 70 hours  E) None of these
Explanation :   Let the required number of hours be x. Then,   Less men, More hours (Indirect Proportion)   15 : 36 : : 25 : x =&gt; (15 * x) = (36 * 25)   x=(36 x 25)/15 = 60   Hence, 15 men can do it in 60 hours.   Answer : 60 hours
<result>C</result>
In power plant, If 36 men can do a piece of work in 25 hours, in how many hours will 15 men do it ?