Question

Tim's electricity costs 4.3 ¢ a kilowatt hour. How much will it cost to run the following appliances for 10 hours? (round to the nearest cent)

a Dryer @ 4,000 watts. Cost =

a Heater @ 1,500 watts. Cost =

a Radio @ 40 watts. Cost =

Answer 1

a Dryer @ 4,000 watts. Cost = 172 cents

a Heater @ 1,500 watts. Cost = 64.5 cents

a Radio @ 40 watts. Cost = 1.72 cents.

Explanation:

Given that cost of 1 kilowatt hour = 4.3 cents.

Then cost of 1 kilowatt for 10 hours = 4.3*10 = 43 cents.

4000 watts = 4000/1000 kilowatt = 4 kilowatts

Then cost for running a Dryer for 10 hours = 4*43 = 172 cents.

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1500 watts = 1500/1000 kilowatt = 1.5 kilowatts

Then cost for running a Heater for 10 hours = 1.5*43 = 64.5 cents.

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40 watts = 40/1000 kilowatt = 0.04 kilowatts

Then cost for running a Radio for 10 hours = 0.04*43 = 1.72 cents.

Answer 2

Electricity consumed by dryer will cost 172¢ , by a Heater 65¢ and by Radio 2¢

Explanation:

As per question Tim's electricity costs 4.3 ¢ a kilowatt hour.

Electricity consumed by a dryer in 10 hours = 10×4000 watts hour

= 10×4 kilo watts hour

= 40 kilowatt hour

And cost of electricity consumed by dryer = 40×4.3 ¢ = 172¢

A heater of 1500 watts will consume the electricity in 10 hours =1500×10 watt hours OR 1.5×10 kilowatt hours = 15 kilowatt hours

So the cost of electricity consumed by heater will be = 15×4.3 = 64.5 ¢ ≅ 65¢

Electricity consumed by Radio in 10 hours = 40×10 watt hours

= 400 watt hours

= 400÷1000 kilowatt hour

= 0.40 kilowatt hour

So the cost of electricity consumed by Radio = 0.40×4.3¢

= 1.72¢ ≅2¢