SOLUTION: I can't seem to get this one started. Please help. Kathy can paint a house in 15 hours. With Jane's help it takes only 6 hours. How long would it take Jane by herself?

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Question 77182: I can't seem to get this one started. Please help.
Kathy can paint a house in 15 hours. With Jane's help it takes only 6 hours. How long would it take Jane by herself?
Answer by rajagopalan(174) (Show Source):
You can put this solution on YOUR website!
kathy....takes...15..hours ..means she paints 1/15 per hour...(A)
kathy+Jane..take..6.. hours ..means they paint 1/6 per hour(..B)
So Jane alone paints (1/6)-(1/15) per hour ..(B-A)=
simplifying, 1/6 minus 1/15=5/30 minus 2/30 = 3/30=1/10
1/10th of the house is painted in one hour by Jane
For full house she will consume 10 hours (invert 1/10)
Cross check
Kathy in one hour 1/15
Jane in one hour 1/10
Both in one hour 1/15..+1/10 = 2/30..+3/30=5/30=1/6
So they will take 6 hours to finish the hoe painting..OK
Good day..
Answer: It takes Jane 10 hours to finish it herself.