Question 572899
Fuel cost for one year = $2025
Price per gallon = $225
Miles driven = 22,500


Fuel cost for one year = (miles driven * price per gallon) / (fuel efficiency rate)

You have everything but the fuel efficiency rate already.  Just need to solve for that.  Let's call that E


So, substituting,
2025 = (22500 * 2.25) / E.

2025 = (50625) / E
To get E in the numerator, we need to multiply each side by E.

2025 * E = 50625
Now divide both sides by 2025 to get E alone.


E = 25.  Fuel efficiency is 25.


The second part of the question gives you a new E, but wants us to calculate the new fuel cost for one year.  So back to the formula:
Fuel cost for one year = (miles driven * price per gallon) / (fuel efficiency rate)
Let C = cost for one year
C = (22500 * 2.25) / 35
C = 1446.43
If the fuel efficiency were 35, the cost per year would have been $1446.43.


The savings would have been:  $2025 - $1446.43 = $578.57