A certain battery charger uses 12 W of power. At 6.0 cents per kilowatt-hour, how much does it cost to charge batteries for a full day?
A) 1.4¢
B) 28¢
C) 1.7¢
D) 75¢
E) 2.3¢

Question

Quizplus · Accepted Answer

The power used is 12 W, which is 0.012 kW. Over 24 hours, the energy used is 0.012 kW * 24 h = 0.288 kWh. At 6.0 cents per kWh, the cost is 0.288 kWh * 6.0 cents/kWh = 1.728 cents, which rounds to 1.7¢.

A Certain Battery Charger Uses 12 W of Power