Math Help - Cost/breakeven/profit

I have been at this for hours and simply cannot figure out how to set this up/

You are offered a job to drive a rental truck 540 miles and back, so 1080 round trip. You will receive $0.55 per mile but it costs $0.42 for gas/truck plus a $39 flat rental rate to rent the truck for the whole trip.

A) what is your break even point in miles?
B)What is your profit when you get to the destination? (540 Miles)
C)What is the profit from the whole trip?

Originally Posted by heffay

I have been at this for hours and simply cannot figure out how to set this up/

You are offered a job to drive a rental truck 540 miles and back, so 1080 round trip. You will receive $0.55 per mile but it costs $0.42 for gas/truck plus a $39 flat rental rate to rent the truck for the whole trip.

A) what is your break even point in miles?
B)What is your profit when you get to the destination? (540 Miles)
C)What is the profit from the whole trip?

$0.42 per what? mile, hour, gallon, ... , ???

Originally Posted by skeeter

$0.42 per what? mile, hour, gallon, ... , ???

Assuming it's $0.42 per mile...

Let be miles. Your cost can be expressed as the function , and your reimbursement can be expressed as .

Originally Posted by heffay

A) what is your break even point in miles?

Equate the two functions above and solve for :

Originally Posted by heffay

B)What is your profit when you get to the destination? (540 Miles)
C)What is the profit from the whole trip?

From the above, can you figure out how to calculate profit? (reimbursement - cost)

got it thanks!