The cost of running a set of eight 100 watt light bulbs for 6 hours, with the cost of electricity at 9¢ per kWh, is approximately:
A) 5¢
B) 24¢
C) 43¢
D) 54¢
E) 72¢

Question

Quizplus · Accepted Answer

To calculate the cost of running a set of eight 100 watt light bulbs for 6 hours, first we need to calculate the total energy used:

Total Energy = Power x Time
Total Energy = 8 bulbs x 100 watts/bulb x 6 hours
Total Energy = 48,000 watt-hours

To convert watt-hours to kilowatt-hours (kWh), we divide by 1000:

Total Energy in kWh = 48,000 watt-hours / 1000
Total Energy in kWh = 48 kWh

Now we can calculate the cost of electricity:

Cost = Energy x Rate
Cost = 48 kWh x $0.09/kWh
Cost = $4.32

To find the cost for 6 hours, we need to divide by the number of hours:

Cost for 6 hours = $4.32 / 6
Cost for 6 hours = $0.72

Therefore, the cost of running a set of eight 100 watt light bulbs for 6 hours, with the cost of electricity at 9¢ per kWh, is approximately 72¢. So, the best choice is C.

The Cost of Running a Set of Eight 100 Watt