Kristen purchased a used car for $32,050 last year and incurred variable operating costs such as gas, oil, tires, maintenance and repairs. She estimates the car will be worth $0 in 5 years, so the annual depreciation is $6,410. She also pays monthly garage fees. To calculate the average cost per mile, we must consider the purchase price, annual depreciation, garage fees and variable operating costs for the 25,000 miles driven last year.