Question

Electricity from the local power company costs 7.22 cents/kWh. A homeowner wishes to pay a maximum of 25 cents per month for the electricity to power a stereo system. For how many hours per month could the stereo system be used?

Answer 1

You haven't said how much power the stereo uses.  It matters !

Whatever that number is, the maximum hours per month is

    (3460) divided by (the # of watts the stereo uses when it's playing) .

Answer 2

Answer:

The power rating of the stereo is not stated and this makes the question incomplete, however, we can make the stereo rating x (this is a basic power calculation)

Explanation:

To calculate the number of hours the homeowner can get,

First, divide the total amount (25cents) by power cost (7.22 cents/kWh) and multiply by 1000 (to convert kilowatt to watt).

This gives us $\frac{3462.6W/h}{x}$ as shown below.

 $\frac{25X1000 }{7.22x}= 3462.6/x$

Finally, whatever the stereo rating is, insert it as x and solve for the number of hours.