Question

Your utility company charges 13 cents per kilowatt-hour of electricity. Complete parts (a) and (b) below.

a. What is the daily cost of keeping lit a 60-watt light bulb for 10 hours each day?
b. How much will you save in a year if you replace the bulb with an LED bulb that provides the same amount of light
using only 15 watts of power?
a. The daily cost of keeping lit a 60-watt light bulb for 10 hours each day is $
(Round to three decimal places as needed.)
b. The yearly savings of replacing the 60-watt light bulb with a 15-watt light bulb is $
(Round to two decimal places as needed.)

Answer 1

Answer: a) $78 per day

b) $21,352.50

Explanation:

a) 60x10=600

600x0.13= $78 per day

b) 15x10=150

150x0.13=$19.50 per day

19.50x365= $7,117.50 per year (with a 15watts lightbulb)

$78x365=$28,470 per year (with a 60watts lightbulb)

$28,470-7,117.50= $21,352.50