15 men can work a do in 12 days. How long it will take 9 men to do work?

15 men can work a do in 12 days. How long it will take 9 men to do work?

Explanation

If 15 men can complete the work in 12 days,

it means that the total number of man-days required to complete the work is:

15 men * 12 days = 180 man-days.

180 man-days / 9 men = 20 days.