SOLUTION: I'm drawing a blank at how to set this equation up - any help would be greatly appreciated! A city's transit authority serves 156,000 commuters daily when the fare is $1.50. Mar

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Question 762313: I'm drawing a blank at how to set this equation up - any help would be greatly appreciated!
A city's transit authority serves 156,000 commuters daily when the fare is $1.50. Market research has determined that every penny decrease in the fare will result in 1,200 new riders. What fare will maximize revenue?
Thank you!

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
A city's transit authority serves 156,000 commuters daily when the fare is $1.50. Market research has determined that every penny decrease in the fare will result in 1,200 new riders. What fare will maximize revenue?
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R(x) = (150-x)(156000+1200x)
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R'(x) = (150-x)*1200 + 156000*(-1)
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Solve: 1200(150-x) - 156000 = 0
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1200x = 1200*150 -156000
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x = 20 cents
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Max fare = $1.50 - 20 = $1.30
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Cheers,
Stan H.