Question

If your electric bill for that and can-distant light was $20 in a month, and you use the CFLs for the same number of hours, what will the new bill be?

Answer 1

The new bill for using CFLs for the same number of hours would be $1.95 for 1000 hours.

Step-by-step explanation:

The new bill for using CFLs for the same number of hours would be $1.95 for 1000 hours.

The CFL uses only 15 W, which is one-quarter the wattage of the incandescent bulb. Therefore, the electricity cost would be $7.20/4 = $1.80.

The CFL also lasts 10 times longer than the incandescent bulb. Thus, the investment cost for the CFL over the same time period would be 1/10 of the bulb cost, or 0.1($1.50) = $0.15.

Adding the electricity cost and the investment cost together, the total cost for using the CFL for 1000 hours would be $1.80 + $0.15 = $1.95.