If it takes 5 workers 20 hours to brick a house, how long will it take 8 workers to do the job if they all work at the same rate?

So 20 / 5 = 4 hours per person and then you need to do 20 / 8

Answer: It's 12.5 hours.

Step-by-step explanation:

12.5 hours is correct. You are increasing the number of men.

5 men * 20 hours = 100 man hours

100 man hours : 8 men = 100 / 8 = 12.5 hours