A new 10-hp motor is required to replace an old one. It will run 500 h per month, and the energy cost is $0.15/kWh. You have two options available: 

(1) A standard motor with 90% efficiency at $1500 cost or 

(2) A high-efficiency motor with 92% efficiency at $2000 cost. Determine the simple and discounted payback periods of investing in the high-efficiency motor at a discount rate of 12% per annum.