Question

darnell's car used 8 gallons of gasoline to travel 340 miles. after a mechanic work on teh 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

What we are going to do for this case is find the cost for each case:
Cost to run the car before the mechanic worked on it:

`(4) * (8) = 32 dollars (32) * (1/340) = 0.09 dollars / mile`
Cost to run the car after the mechanic worked on it:

`(4) * (7) = 28 dollars (28) * (1/350) = 0.08 dollars / mile`
The difference between both cases is:

`0.09 - 0.08 = 0.01 dollars / mile`
Answer:
It cost to run the car after the mechanic worked on it 0.01 $ / mile less than before the mechanic worked on it.