300 mens were engaged to complete a job in a certain number of days. but due to another assignment 15 men dropped the 2nd day, 15 more men dropped the 3rd day and so on.it takes 15 more days to finish the work now. find the number of days in which the work was completed.

Ummhh, what am I missing?

Didn't you just state that it takes 18 days to finish the work ?