A landlord has eight 40W electric light bulbs, four 60W bulbs and two 100W bulb...

JAMB 1979

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

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Correct Answer: Option A

Explanation

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

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