An electric lamp is rated 240V, 40W. What is the cost of running the lamp for 72 hours if the electricity authority charges N2.50 per kWh?
-
A.
N7.20 -
B.
N18.00 -
C.
180.00 -
D.
N720.00
Correct Answer: Option A
Explanation
Cost = (frac{Pt}{1000}) x cost per kWh
= (frac{40 times 72}{1000} times 2.50 = N7.20)