36 Men Can Do Piece Of Work In 7 Days

36 men can do a piece of work in 7 days. How many men will do the same work in 42 days?

Answers:

Men : Days :: Men : Days

36    :    7     ::    x     :   42

∴ By inverse proportional

36 × 7 = x × 42

⇒ x = (36 × 7)/42 = 6 men