Question

the total cost of 15 gallons of regular unleaded gasoline and 10 gallons of premium unleaded gasoline is $35.50. premium unleaded costs $0.20 more per gallon than regular unleaded. what is the cost per gallon of each type?

Answer 1

Explanation:

15r + 10p = 35.50

p = r + 0.20

15r + 10(r + 0.20) = 35.50

15r + 10r + 2 = 35.50

25r = 35.50 - 2

25r = 33.50

r = 33.50 / 25

r = 1.34 <===== regular is 1.34 per gallon

p = r + 0.20

p = 1.34 + 0.20

p = 1.54 <==== premium is 1.54 per gallon