SOLUTION: alice can wash he car in 3 and 1/2 hours if bernice helped her she can do the job in 2 hours. how long would it take if bernice working alone

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: alice can wash he car in 3 and 1/2 hours if bernice helped her she can do the job in 2 hours. how long would it take if bernice working alone      Log On


   



Question 919595: alice can wash he car in 3 and 1/2 hours if bernice helped her she can do the job in 2 hours. how long would it take if bernice working alone
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
Alice can wash her car in 3 and 1/2 hours
if Bernice helped her she can do the job in 2 hours.
how long would it take if Bernice working alone?
:
let b = time required by Bernice working alone
let the completed job = 1
:
Each will do a fraction of the job, the two fractions add up to 1
2%2F3.5 + 2%2Fb = 1
multiply eq by 3.5b, cancel the denominators and you have
2b + 3.5(2) = 3.5b
2b + 7 = 3.5b
7 = 3.5b - 2b
7 = 1.5b
b = 7/1.5
b = 42%2F3 hrs Bernice working alone
:
:
you can check this for yourself, see if the equation is true
2%2F3.5 + 2%2F4.6667 = 1