Answer: 387 1/2 miles
Explanation:
From the question, we know that 20 gallons can be used for 500 miles. Therefore, the gallons of gas per mile will be:
= 500/20
= 25 gallons per mile.
The number of miles that a 15 1/2 gallons will use will be:
= 25 × 15 1/2
= 387 1/2 miles