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Question 992627: Craig and Pam, working together, can mow the lawn in 9 hours. Working alone, Pam takes three times as long as Craig. How long does it take Craig to mow the lawn alone?
Found 2 solutions by stanbon, lwsshak3:
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! Craig and Pam, working together, can mow the lawn in 9 hours. Working alone, Pam takes three times as long as Craig. How long does it take Craig to mow the lawn alone?
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Together rate:: 1/9 job/hr
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Craig rate:: 1/x job hr
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Pam rate:: 1/(3x) job/hr
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Equation:
rate + rate = together rate
1/x + 1/(3x) = 1/9
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Multiply thru by 9x to get:
9 + 3 = x
x = 12 hrs (time for Craig alone)
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Cheers,
Stan H.
Answer by lwsshak3(11628) (Show Source):
You can put this solution on YOUR website! Craig and Pam, working together, can mow the lawn in 9 hours. Working alone, Pam takes three times as long as Craig. How long does it take Craig to mow the lawn alone?
let x=hours it takes Craig to mow the lawn alone
1/x=his work rate
3x=hours it takes Pam to mow the lawn alone
1/3x=her work rate
sum of indv. work rates=work rate working together
1/x+1/3x=1/9
lcd:9x
9+3=x
x=12
hours it takes Craig to mow the lawn alone=12
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