Suppose x men will be required to complete the job in 40 days
∵ To complete a job in 4 days the required men are 20 .
∴ To complete the job in 1 day the required men are 20×4 .
( explanation: in 1 day more men will be needed to complete the same job, therefore for more men multiplication has been done.)
∴ To complete the job in 40 days the required men are (20×4)/40 .
|explanation:lesser number of men will be needed to complete the job in 40 days in comparison to one day. Therefore division has been by 40|
= 2 men Ans.