A 400-W computer (including the monitor)is turned on for 8.0 hours per day.If electricity costs 10¢ per kWh,how much does it cost to run the computer annually for a typical 365-day year?
A) $120
B) $1200
C) $15
D) $17
E) $150

Question

Quizplus · Accepted Answer

The computer uses 400 W of power for 8 hours per day, so it uses 400 W * 8 h/day = 3200 Wh/day of energy. In a year, it uses 3200 Wh/day * 365 days/year = 1,168,000 Wh/year of energy. At a cost of 10¢ per kWh, the cost to run the computer for a year is 1,168,000 Wh/year * 10¢/kWh = $116.80, which is closest to $120.

A 400-W Computer (Including the Monitor)is Turned on for 8