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Question 1076672: Jim paints a house in half an hour. Jane paints a house in 1/5 of an hour. If Jim works for 10 minutes and then Jane joins him, how long will it take them to complete 1 whole house together?
I'm not sure if I'm doing this correctly, please help!
I set up the problem to first figure out how much work Jim has done prior to Jill joining.
Jim paints a house in a half hour or 1/30
He works for 10 minutes
Jim 1/30 *10 = .3
Now work total is 1, thus we take 1-.3 = .70 work left
Jane now joins who paints at 1/5 of an hour (1/5 an hour being 12 minutes)
1/30 + 1/12 = .70t
=2/60 + 5/60 = .70t
=7/60 =.70/t
Cross multiply
=7t=42
42/6
t=6
They finish the house Together in 6 minutes?
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! m paints a house in half an hour. Jane paints a house in 1/5 of an hour. If Jim works for 10 minutes and then Jane joins him, how long will it take them to complete 1 whole house together?
I'm not sure if I'm doing this correctly, please help!
I set up the problem to first figure out how much work Jim has done prior to Jill joining.
Jim paints a house in a half hour :: rate = 1/30 job/min
He works for 10 minutes
Jim 1/30 *10 = 1/3 job
Now work total is 1, thus we take 1-.3 = 2/3 job left
Jane now joins who paints at rate of 1/5 job/hr (1/5 an hour being 12 minutes)
t(1/30 + 1/12) = 2/3 job
t((12+30)/(12*30)) = 2/3
t(42/360) = 2/3
t = (360/42)(2/3) = 120/21 = 5.71 min = 5 min 42 sec
t is time to finish the job together.
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Cheers,
Stan H.
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