Optimization, minimize cost [closed]

A trucking company has hired you to determine the optimal highway speed, v, they should require of their drivers to minimize cost. The decision is to be based solely on economic grounds. You only need to consider:

1) driver's hourly wage (W) , and

2) price of fuel (P) , measured in \$ per gallon.

The formula for the rate of fuel consumption is:

r = 9.34(miles/gallon) -0.0596(hours/gallon)*v

where r is in miles per gallon and v is in miles per hour.

Determine the formula that would be used to calculate the optimal speed for any values of W and P.

I have been stuck on this question for several hours now. I dont know how to get the mpg into the equation. Also do I have to use the formula for the rate of fuel consumption? Any advice on where or how to start would be great.

closed as off-topic by user44191, Alexey Ustinov, Yemon Choi, RP_, David RobertsApr 16 at 6:14

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