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!