Question

A 180-watt iHome® is used on an average of three hours a day. Find the cost of listening to the iHome for one week at a cost of $0.13 per kilowatt-hour.
A. $0.49

B. $11.34

C. $491.40

D. $0.07

Answer 1

Hello!

The answer is:

The correct option is:

A. $0.49

Why?

From the statement, we know that the iHome is used on average three hours a day, and we are asked to find the cost for a week, so first, we need to calculate the total hours that the iHome is used for, and then, calculate the kilowatt-hour consumption rate.

$TotalTime_{week}=3\frac{hours}{day} *7days=21hours$

$TotalEnergyConsumption_{week}=180watt*21hours=3780watt.hour$

Now, we must remember that:

$1Kilowatt=1000watts$

So,

$3780watts=3780watts.hour*\frac{1KiloWatt}{1000watts}=3.78KiloWatt.hour$

Then, calculating the cost, we have:

$TotalCost_{week}=0.13\frac{dollar}{killowat.hour}*3.78killowat.hour=0.49(dollar)$

Hence, we have that the correct option is:

A. $0.49

Have a nice day!