What is the cost of running seven 40 W lamps and five 80 W lamps for 12 hours of the electrical energy cost N7.00kWh?

VictorKachi

6 years ago

Total power consumed: (7X40W) + (5X80W) = 280W + 400W = 680W
.
Converting to kW: 680W/1000 = 0.68kW
.
Obtaining kilowatt hour = 0.68kW X 12hours = 8.16kW/h
.
Cost conversion:
1kWh ===> N7
8.16kWh ===> x
Cross multiply,
x = 8.16kWh X N7
x = N57.12

TCSS2025B

4 months ago

sharp

DominicAfam

1 year ago

Total power=280+400
=680w

Convert w to kw
680/1000=0.68kw

1kw/h = N7
0.68kw/12=Nx? 😭
Cross multiply
x=7×0.68×12
x=N57.12😂


✌️

Velapearl

2 months ago

Power: 7 × 40 = 280 W
5 × 80 = 400 W
Total power = 680 W
Energy = P × t
= 680 × 12
= 8160 Wh
Convert to kWh:
8160 ÷ 1000 = 8.16 kWh
Cost = 8.16 × 7
= 57.12
Answer = ₦57.12