SOLUTION: maria wax her car in 2 hours when she works with susan they can wax the car in 45 mins. how long will it take susan working by herself to wax the car?
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Question 162043: maria wax her car in 2 hours when she works with susan they can wax the car in 45 mins. how long will it take susan working by herself to wax the car? Answer by ankor@dixie-net.com(22740) (Show Source):
You can put this solution on YOUR website! Maria waxes her car in 2 hours. When she works with Susan, they can wax the car
in 45 mins. How long will it take Susan, working by herself, to wax the car?
:
Let x = time required by Susan by herself
:
Change 45 min to hrs: 45/60 = .75 hrs
:
Let the completed job = 1
:
Each will do a fraction of the job and will add up to 1
: + = 1
Multiply equation by 2x to eliminate the denominators, solve for x
.75x + 2(.75) = 2x
:
.75x + 1.5 = 2x
:
1.5 = 2x - .75x
:
1.5 = 1.25x
x =
x = 1.2 hrs, for Susan to do the job by herself
:
:
Check solution on a calc
.75/2 + .75/1.2 = 1
