<PRE><B>Question 137252</B>
A carpenter charges a set fee for each job in additon to his hourly charge. If a carpenter bills a customer $150 for a job which takes him 3 hours and bills a second customer $180 for a 6 hour job, how much would he charge for a job that takes him 9 hours?
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You have two points relating time and charge: (3,150) and (6,180)
slope = 30/3 = 10
150 = 10*3 + b
b = 120
EQUATION:
charge = 10(hrs)+120
C(9) = 10*9 + 120
C(9) = $210 (charge for a 9 hour job)
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Cheers,
Stan H.</PRE>