The answer is:
The correct option is:
A. $0.49
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.
[tex]TotalTime_{week}=3\frac{hours}{day} *7days=21hours[/tex]
[tex]TotalEnergyConsumption_{week}=180watt*21hours=3780watt.hour[/tex]
Now, we must remember that:
[tex]1Kilowatt=1000watts[/tex]
So,
[tex]3780watts=3780watts.hour*\frac{1KiloWatt}{1000watts}=3.78KiloWatt.hour[/tex]
Then, calculating the cost, we have:
[tex]TotalCost_{week}=0.13\frac{dollar}{killowat.hour}*3.78killowat.hour=0.49(dollar)[/tex]
Hence, we have that the correct option is:
A. $0.49
Have a nice day!
