Your parents allow you to borrow a car to get to your part-time job, but you have to pay for a tank of gas each month. gasoline costs $2.76/gallon and the tank takes 15 gallons. you have 2 coworkers who are each willing to pay for a quarter of a tank each month to carpool with you to work. how much do you save each month?

$20.70

$18.55

$15.91

$16.46

The answer to this question is the letter "A" which is $20.70. The solution is shown below:

If the guy will solely use the car, his expenses for the gasoline per month is:
Guy alone = $ 2.76/gallon * 15 gallons = $ 41.4
 
If the guy will let his two officemates ride the car and contribute each quarter of the of a tank:
First officemate = 15/4 * $2.76 = $ 10.35
 Second officemate = 15/4 * $2.76 = $10.35

The guy total savings is shown below:
Total savings = $41.4 - $10.35 -$10.35
Total savings = $20.70

The answer is the letter "A".