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rosijanka [135]

2 years ago

9

a man uses a 900 watt electric iron to press his clothes for an average of 4 hours a week for five weeks if the cost of an elect

ric energy is 3 Kobo per unit calculate the cost of electric energy for pressing

2 answers:

qaws [65]2 years ago

5 0

Answer:

$\boxed{\sf54 \: kobo}$

Explanation:

Energy = Power × Time

Energy = 900× 4 ×5 = 18000 wh

Energy = 18000 wh = 18 kwh

Cost of 1 unit electricity = 3 kobo

cost of 18 unit electricity= 18 × 3 = 54 kobo

ser-zykov [4K]2 years ago

4 0

Answer:

54 Kobo

Explanation:

Units of <u>electricity</u> are measured in kilowatt hours (kWh).

Given information:

900 watt electric iron
Appliance usage = 4 hours a week for 5 weeks
Unit cost of electricity = 3 Kobo per kWh

<h3><u>Step 1</u></h3>

Convert the wattage of the electric iron from watts to kilowatts.

1000 watts (W) = 1 kilowatt (kW)

⇒ 900 watts = 1 ÷ 1000 = 0.9 kilowatts

This means that the power consumption of the electric iron is 0.9 kW per hour of use.

<h3><u>Step 2</u></h3>

Total hours spent pressing clothes:

= 4 hours per week for 5 weeks

= 4 × 5

= 20 hours

<u>Total power consumption</u>:

= number of kW × number of hours

= 0.9 × 20

= 18 kWh

<h3><u>Step 3</u></h3>

To find the <u>total cost</u>, multiply the total kWh by the cost per kWh:

⇒ Cost = 18 × 3 = 54 Kobo

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