Please revaluate the right solution of the given Problem
Problem- A Large facility has 350 two-lamp fixtures, and each fixture is using 253 Watts. Improved ballasts can save 48 W/fixture. The facility operates with one- 8 hours shift each day, 5 days a week, and 50 weeks/year. The demand peak is during the daytime. Present electrical costs are $0.10/kWh/month with a demand charge of $4.50/kW/month.
Part 1- What is the simple payback period on this investment if the cost of each new fixture is $12.0?
I want help to find the simple payback period on the investment.