Question

If your car gets 28 miles per​ gallon, how much does it cost to drive 390 miles when gasoline costs ​$2.90 per​ gallon?

Answer 1

Answer: x = $25.89

Step-by-step explanation:

This is a two step problem.  First we need to determine the number of gallons the car uses to drive the 250 miles:

250/28 ≈ 8.93 gallons

Then we just multiply the number of gallons by the price:

8.93 x 2.90 = $25.90

Alternate solution:  Use a proportion.  Since 1 gallon costs $2.90 and produces 28 miles, we can set up the following proportion:

2.90/28 = x/250

Cross-multiply and solve:

28x = 725

x = $25.89 (There is a one cent difference due to a rounding error in the first solution.  This solution avoids that error.)