Answer and Explanation:
The computation is shown below:
a. The number of miles driven per year is
Let us assume the mileage be M
Now
$499 + M ($3 ÷ 50) = $399 + M ($3 ÷ 25)
$100 = M(0.12 - 0.06)
M = $100 ÷ 0.06
= 1,666.66 miles per month
For year, it is
= 1,666.66 × 12
= 20,000 miles per year
c. Now in the case when the gasoline price is $4 per gallon
$499 + M ($4 ÷ 50) = $399 + M ($4 ÷ 25)
$100 = M(0.16 - 0.08)
M = $100 ÷ 0.08
= 1,250 miles per month
For year, it is
= 1,250 × 12
= 15,000 miles per year