On a cold night a house is losing heat at a rate of 80,000 Btu/h. A reversible

Question:

On a cold night a house is losing heat at a rate of 80,000 Btu/h. A reversible heat pump maintains the house at 70oF, while the outside temperature is 30oF. Determine
(a) The heating cost for the night (8 hours) assuming the price of 10 cents/kWh for electricity. Also determine
(b) The heating cost if resistance heating were used instead.