Question 1203763
It takes 20 men 60 days to complete a building work.

how many days longer would it take 15 men, assuming that they all work at the same rate (formula method)

In this problem itis a case of inverse proportion.

W1 *M1=W2*M2

20*60 = 15*x

(20/15) *60 =x
= 80 days
So 15 men will take 20 days more to complete the job