SOLUTION: pam and craig, working together, can mow the lawn in 8 hours. working alone craig takes twice as long as pam. How long does it take pam.

Algebra ->  Rate-of-work-word-problems -> SOLUTION: pam and craig, working together, can mow the lawn in 8 hours. working alone craig takes twice as long as pam. How long does it take pam.      Log On


   

Question 757742: pam and craig, working together, can mow the lawn in 8 hours. working alone craig takes twice as long as pam. How long does it take pam.
Answer by josgarithmetic(39625) About Me  (Show Source):
You can put this solution on YOUR website!
The rates of each person working together are additive.
p for pam's rate and c for craig's rate.
pam works two times the rate of craig.

p=2c
The rates in jobs per hour are these:
craig: 1%2F%282h%29
pam: 1%2F%28h%29
h is the time for craig to do the job alone. The direct use of p=2c seems not needed although represents the description.

Equation: highlight%281%2F%282h%29%2B1%2Fh=1%2F8%29 remember the unit is jobs per hour.

Solve for h.
2h%2A%281%2F%282h%29%29%2B2h%281%2Fh%29=2h%2F8
1%2B2=h%2F4
h=12

Time each needs to do the job:
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Pam, h/1 = 12 hours___________
Craig, 2h/1 = 24 hours_________
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