Question

If electricity costs 5 cents per kilowatt-hour, how much does it cost to run an 80-watt light bulb for 24 hours?96.0 cents 4.2 cents 5.6 cents 9.6 cents description

Answer 1

We are given the electricity cost as 5 cents per kilowatt-hour. We should notice that the cost is actually in the form of:

electrical cost = cost / (power * time)

Therefore to get a number which is in terms of cents alone (cost alone), therefore we should multiply the given electrical cost value with the power and time.

Power = 80 watt = 0.08 kilowatt

Time = 24 hours

 

Therefore the cost is calculated as:

cost = electrical cost * power * time

cost = [5 cents / (kilowatt hour)] (0.08 kilowatt) (24 hour)

cost = 9.6 cents

 

Answer:

9.6 cents