Question

On a particular day, the following appliances are used for the times indicated: a 1600-W coffee maker, 19 min, and a 1100-W microwave oven, 3.5 min. With these power requirements, find how much it costs to use these appliances at an electrical cost of 7¢ per kWh. (Do not round your final answer. Fractional cent values are acceptable.) answer with:___¢

Answer 1

The first step is to convert the times from minutes to hours.

Recall,

60 min = 1 hour

19 min = 19/60

3.5 min = 3.5/60

Considering the 1600-W coffee maker,

Consumption = 1600 x 19/60 = 506.67 kwh

Considering the 1100-W microwave oven,

Consumption = 1100 x 3.5/60 = 64.17 kwh

Total consumption = 506.67 + 64.17 = 570.84 kwh

Given that the cost is 7¢ per kWh,

cost of using these appliances = 570.84 x 7

cost of using these appliances = 3995.88¢