Under either option, Monument Valley would hire a tour guide for $220 for the trip. Monument Valley has extra cars in its switching yard, and it would cost $45 to move a car to the main track and hook it up. The extra fuel cost to pull one extra car is $0.20 per mile. To run an engine and a passenger car on the trip would cost $2.00 per mile, and an engineer would be paid $420 for the trip. Depreciation on passenger cars is $5,300 per year, and depreciation on engines is $21,200 per year. Each passenger car and each engine travels about 50,000 miles a year. They are replaced every 8 years The agent offered to pay $31 per passenger for the special tour and $16 per passenger for simply adding an extra car. Under either option, Monument Valley would hire a tour guide for $220 for the trip. Monument Valley has extra cars in its switching yard, and it would cost $45 to move a car to the main track and hook it up. The extra fuel cost to pull one extra car is $0.20 per mile. To run an engine and a passenger car on the trip would cost $2.00 per mile, and an engineer would be paid $420 for the trip. Depreciation on passenger cars is $5,300 per year, and depreciation on engines is $21,200 per year. Each passenger car and each engine travels about 50,000 miles a year. They are replaced every 8 years The agent offered to pay $31 per passenger for the special tour and $16 per passenger for simply adding an extra car