Running a clothes dryer for 90 minutes at 800 Watts will cost about ______ cents if the cost of electricity is 7 cents per kWh:
A) 4
B) 10
C) 24
D) 50
E) 120

Question

Quizplus · Accepted Answer

To calculate the cost, first find the total energy used in kilowatt-hours (kWh). The dryer uses 0.8 kW (since 800 Watts = 0.8 kW) and runs for 1.5 hours (90 minutes), so the energy used is 0.8 kW * 1.5 hours = 1.2 kWh. At a cost of 7 cents per kWh, the total cost is 1.2 kWh * 7 cents/kWh = 8.4 cents, which rounds to approximately 10 cents.

Running a Clothes Dryer for 90 Minutes at 800 Watts