SOLUTION: How do I solve this? Sally can paint a house in 4 hours. It takes John 6 hours to paint the same house. How long does it take them together?
I am not sure how to set this u
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I am not sure how to set this u
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Question 253585: How do I solve this? Sally can paint a house in 4 hours. It takes John 6 hours to paint the same house. How long does it take them together?
I am not sure how to set this up.
Thanks!
Lisa Comer Found 3 solutions by jim_thompson5910, drk, stanbon:Answer by jim_thompson5910(35256) (Show Source):
You can put this solution on YOUR website! This is job /time. We want the job over time for Sally and for John. We want the time together, x. So we have
(1/4)x + (1/6)x = 1
step 1 - multiply by 12 to get
3x + 2x = 12
5x = 12
x = 12/5.
2.4 hours.
You can put this solution on YOUR website! How do I solve this? Sally can paint a house in 4 hours. It takes John 6 hours to paint the same house. How long does it take them together?
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Sally's rate: 1/4 job/hr
John's rate: 1/6 job/hr
Together rate: 1/x job/hr
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Equation:
rate + rate = together rate
1/4 + 1/6 = 1/x
Multiply thru by 12x
3x + 2x = 12
5x = 12
x = 12/5 = 2.4 hrs (time to do the job if Sally and John work together.
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Cheers,
Stan H.
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