You han an 1800 watt hair dryer that you use for an average of 10 minutes per day. Your utility company charges 12 cents per kilowatt hour of energy. How much does it cost to run the hair dryer each day? each year?

The first thing you need to do is isolate the numbers from your problem:

1800 watt hours times (x) 10 min per day

12 cents per kilowatt hour

Then convert into the same terms

$0.12 per 1000 watt hours

1800 watts for 10 min. divided by 60, or 0.167 hours

Then multiply 1800 by 0.167 by $0.12 and get $0.036 for the cost per day

Multiply that answer by the number of days in a year (365 or 366 for a leap year)

and get your answer!