The hallways of a university are lit by 40 fluorescent lights, each containing two lamps rated at \(60 \mathrm{~W}\) each. The lights are on all day and night during the year, but the building is only used from 7 a.m. to 7 p.m. 5 days per week during the year. If the price of electricity is 7 cents \(/ \mathrm{kWh}\), estimate the amount of energy and money that could be saved by installing two motion sensors that turn off the lights when the building is not being used. Then, estimate the simple payback and the payback with a \(6 \%\) effective interest rate if the price of a sensor is \(\$ 50\) and the cost of installation is \(\$ 40\).