A house has ten 40W and five 100W bulbs. How much will it...
A house has ten 40W and five 100W bulbs. How much will it cost the owner of the house to keep them lit for 10 hours if the cost of a unit is 5N?
N90
N50
N45
N5
Correct answer is C
P = 40 x 10 + 100 x 5
P = 400 + 500 = 900W
Cost = \(\frac{900 \times 10 \times 5}{1000}\)
Cost = N45