Question

Carmichael's car used 8 gallons of gasoline to travel 340 miles after mechanic worked on the car it used 7 gallons of gasoline to travel 350 miles if the price of gasoline was approximately 4.00 per gallon. , how much less to the nearest cent per mile did it cost to run the car after the mechanic worked on it

Answer 1

Before the work was done, the cost was ...
($4/gal)*(8 gal)/(340 mi) = $32.00/(340 mi)

After the work was done, the cost was ...
($4/gal)*(7 gal)/(350 mi) = $28.00/(350 mi)

The savings is the difference of these costs:
(32.00/340 -28.00/350) $/mi ≈ $0.01/mi

After the mechanic worked on the car, it cost about $0.01 per mile less to run.