What is the cost of running five 50W lamps and four 100W lamps for 10 hours if electrical energy costs 2 kobo per kWh?

djayenimoney

4 years ago

Here's a shortcut.
Find total Power
I.e (50*5)+(100*4)= 650watt=0.6kw

Make sure your units are consistent
Then multiply all through
I.e 0.65*10*2=13kobo=N0.13

If they only gave one power, check if the units are consistent, the multiply all through

DrOge

1 year ago

50*5=250
100*4=400
250+400=650
convert watt to kilowatt
650/1000=0.65
0.65*2/10=0.13.