00:01
Given that the cost of electricity is 9 cents per kilowatt hour, we'd like to calculate how much it costs to use a 3 -watt electric clock for one year.
00:10
Okay, well, one year we have to convert into hours, since this is a unit provided for the energy calculation.
00:19
Well, one year, we can multiply by the amount of days first.
00:29
We have 365 days in one year, and then we want to get from days into hours.
00:35
And of course there's 24 hours in one day.
00:41
So these units cancel, these units cancel.
00:46
We'll be left with hours here.
00:49
So all we have to do is multiply these conversion factors.
00:52
And we get 365 times 24 hours in a year.
00:57
8 ,760 hours...