SOLUTION: If it takes 2 people 8 hours to clean a house, then how many should it take 3 people. Also how long should it take with 3 people on a house that takes 1 1/2 hours with 2 people

Algebra ->  Rate-of-work-word-problems -> SOLUTION: If it takes 2 people 8 hours to clean a house, then how many should it take 3 people. Also how long should it take with 3 people on a house that takes 1 1/2 hours with 2 people      Log On


   

Question 995390: If it takes 2 people 8 hours to clean a house, then how many should it take 3 people.
Also how long should it take with 3 people on a house that takes 1 1/2 hours with 2 people.
Answer by josgarithmetic(39614) About Me  (Show Source):
You can put this solution on YOUR website!
One job is clean a house.
r, one person's rate in job/hour.
t, how many hours for the first question.
system%282%2Ar%2A8=1%2C3r%2At=1%29

Both represent the one job.
2r%2A8=3rt
t=%282%2A8%2Ar%29%2F%283%2Ar%29
highlight%28t=16%2F3%29------this many hours, or 5 hours 20 minutes.


The second question simply uses different given values but is basically the same form.
%281%261%2F2%29hours=%283%2F2%29hours
-
r will be a different value than in the first question but the concept and form are the same.
system%282r%283%2F2%29=1%2C3r%2At=1%29
You can finish this, to solve the system for t.