Please help solve part B

In this problem, we consider replacing an existing electrical water heater with an array of solar panels. The net installed investment cost of the panels is $1.200 ( $2,000 less a 40% tax credit from the government). Based on an energy audit, the existing water heater uses 210 kilowatt hours (kWh) of electricity per month, so at $0.13 per kWh, the cost of operating the water heater is $27.3 per month. Assuming the solar paneis can save the entire cost of heating water with electricity, answer the tollowing questions. a. What is the simple payback period for the solar panels? b. What is the IRR of this investment if the solar panels have a life of 12 years? a. The simple payback penod is months. (Round to the nearest whole number) b. The IRR of the investment is 2 per month. (Round to two decimal places)