In your four years at college you dry your hair everyday for 5 minutes with a 1200-W hairdryer.If the average price of electrical energy was $0.085 per kilowatt-hour,how much did it cost you during this time? (Assume 1 year = 365 days.)

Question

Quizplus · Accepted Answer

First, calculate the total energy used over four years: 1200 W = 1.2 kW, and drying time is 5 minutes per day. In hours, this is 5/60 hours per day. Over four years (4 * 365 days = 1460 days), the total energy used is 1.2 kW * (5/60) hours/day * 1460 days = 146 kWh. The cost is then 146 kWh * $0.085/kWh = $12.41, which rounds to $12.4.

In Your Four Years at College You Dry Your Hair