What is the cost of running seven 40 W lamps and five 80 W la mps for 12 hours of the electrical energy cost N7.00kWk?
Answer Details
To calculate the cost of running the lamps, we need to determine the total energy consumed in kilowatt-hours (kWh) and multiply it by the cost of electrical energy per kWh.
First, let's calculate the total power consumption of the lamps:
Total power consumption = (7 x 40 W) + (5 x 80 W) = 280 W + 400 W = 680 W
Next, let's convert the power consumption to kWh:
Energy consumption = (680 W / 1000) x 12 hours = 8.16 kWh
Finally, let's calculate the cost of running the lamps:
Cost = Energy consumption x Cost of electrical energy per kWh
Cost = 8.16 kWh x N7.00/kWh = N57.12
Therefore, the cost of running seven 40 W lamps and five 80 W lamps for 12 hours at an electrical energy cost of N7.00/kWh is N57.12. The correct answer is option D.