Question 305143: Working together,Andrea and Lisa can clean a 2,000 square foot house in 4.5 hours. Working alone, Lisa can clean a 2,000 square foot house in 6 hours. How long will it take Andrea to clean a 2,000 square foot house?
Answer by nerdybill(7384)   (Show Source):
You can put this solution on YOUR website! Working together,Andrea and Lisa can clean a 2,000 square foot house in 4.5 hours. Working alone, Lisa can clean a 2,000 square foot house in 6 hours. How long will it take Andrea to clean a 2,000 square foot house?
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Let x = time it takes for Andrea to clean the house by herself
then
4.5(1/6 + 1/x) = 1
Multiplying both sides by 6x:
4.5(x + 6) = 6x
4.5x + 27 = 6x
27 = 1.5x
18 hours = x
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