SOLUTION: A group of 18 people can paint a house in 21 days. If the house needs to be painted in 14 days, how many more people are required? I figured out the rate of people per day, but

Algebra ->  Rate-of-work-word-problems -> SOLUTION: A group of 18 people can paint a house in 21 days. If the house needs to be painted in 14 days, how many more people are required? I figured out the rate of people per day, but      Log On


   



Question 532457: A group of 18 people can paint a house in 21 days. If the house needs to be painted in 14 days, how many more people are required? I figured out the rate of people per day, but then I get 12 or 16 people needed. That doesn't make sense because you need more people to get the job done faster. Help, please?
Answer by lwsshak3(11628) About Me  (Show Source):
You can put this solution on YOUR website!
A group of 18 people can paint a house in 21 days. If the house needs to be painted in 14 days, how many more people are required? I figured out the rate of people per day, but then I get 12 or 16 people needed. That doesn't make sense because you need more people to get the job done faster.
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Think in terms of man-days required to paint the house.
18 people painting the house for 21 days=21*18=378 man-days
If you need to paint the same house in 14 days, it would still require 378 man-days.
So you need more men like 378/14=27 men
27 men * 14 days =378 man-days
ans:
13 more people are required to paint the house in 14 days.