A landlord has eight 40W electric light bulbs, four 60W bulbs and two 100W bulb in his house. If he has all the points on for five hours daily and if N.E.P.A. charges 5k per unit, his bill for 30 days is
A
N5.70
B
N7.23
C
N3.65
D
N8.05
E
N4.50
Verified Correct Answer: A.
Physical Principles & Numerical Solution
Total power = (8 x 40) + (40 x 60) + (2 x 100)
= 760W
Energy(Kwhr) = power x time
= 760 x 10-3 x 150
= 114kwhr.
If, 1kwhr. cost 5k
thus, 114 kwhr. will cost 5 x 114
= N5.70
Source: Myschool Past Questions Archive (Record #29198)