SOLUTION: The total cost of 10 gallons of regular gasoline and 15 gallons of premium gasoline is $32.75. Premium costs $.20 more per gallon than regular. What is the cost of gallon of each

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: The total cost of 10 gallons of regular gasoline and 15 gallons of premium gasoline is $32.75. Premium costs $.20 more per gallon than regular. What is the cost of gallon of each      Log On


   

Question 271597: The total cost of 10 gallons of regular gasoline and 15 gallons of premium gasoline is $32.75. Premium costs $.20 more per gallon than regular. What is the cost of gallon of each type of gasoline?
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
The total cost of 10 gallons of regular gasoline and 15 gallons of premium gasoline is $32.75. Premium costs $.20 more per gallon than regular. What is the cost of gallon of each type of gasoline?
--------------------
Equations:
10r + 15p = 32.75
p = r + 0.20
-------------------
Substitute for "p" and solve for "r":
10r + 15(r+0.20) = 32.75
10r + 15r + 2 = 32.75
25r = 30.75
r = $1.23 (price of regular)
---
p = r+0.20
p = $1.43
==================
Cheers,
Stan H.