if 36 men can do a piece of work in 25 hours , in how many hours will 12 men do it ?
"explanation : let the required no of hours be x . then less men , more hours ( indirect proportion ) \ inline \ fn _ jvn \ therefore 12 : 36 : : 25 : x \ inline \ fn _ jvn \ leftrightarrow ( 12 x x ) = ( 36 x 25 ) \ inline \ fn _ jvn \ leftrightarrow \ inline \ fn _ jvn x = \ frac { 36 \ times 25 } { 12 } = 75 hence , 12 men can do it in 75 hours . answer : e ) 75"
divide(multiply(36, 25), 12)