This is a two part question, please answer by hand

Your company needs to purchase a new track hoe and has narrowed the selection to two pieces of equipment. The first track hoe costs $100,000 and has an hourly operation cost of $31.00 and a $35,000 salvage value at the end of three years. The second track hoe costs $65,000 and has an hourly operation cost of $36.00 and no salvage value at the end of three years. The operator cost is $29.00 per hour. The revenue from either track hoe is $95.00 per hour. Using 1,200 billable hours per year and a MARR of 20%, calculate the NPV for both track hoes. Which track hoe should your company choose?

Determine the incremental rate of return for Problem 1. Which track hoe should your company choose?