You are tired of sharing a refrigerator with your roommate, so you decide to buy your own mini-fridge. You can buy a highly energy efficient mini-fridge at a cost of $100.00, or a normal mini-fridge at a cost of $80.00. The high-efficiency refrigerator uses 60. kWh/year (25.0% less energy than the normal refrigerator). The refrigerators each last 10.0 years, and the alternative use of the money would be to reduce your debt on a student loan with an interest rate of 5.00%/year. Assume electricity costs $0.150/kWh. Neglect inflation and the salvage value of the mini- fridges - this one is going on the sidewalk when you graduate. [60 points] a. What is the simple payback time for buying the energy efficient minifridge instead of the normal mini-fridge? (20 points) b. What is the cost of conserved energy and annual energy cost savings for the high-efficiency refrigerator? (10 points)