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A television (65 W), a refrigerator (1.2 kW), an electric kettle (850 W), and 10 lamps (40 W each) are connected in series in a house. How much will it cost the housekeeper to switch on the electricity if it is 15 Kobo per kWh?



Answer :

GinnyAnswer
To determine the total cost of operating the household appliances, let's break down the problem into a step-by-step solution:

### Step 1: Convert the power consumption of each appliance to kilowatts (kW)

1. Television:
- Power consumption: 65 watts (W)
- Conversion to kilowatts (kW): [tex]\( \frac{65}{1000} = 0.065 \)[/tex] kW

2. Refrigerator:
- Power consumption: 1.2 kilowatts (kW)
- No conversion needed since it's already given in kilowatts.

3. Electric Kettle:
- Power consumption: 850 watts (W)
- Conversion to kilowatts (kW): [tex]\( \frac{850}{1000} = 0.85 \)[/tex] kW

4. Lamps:
- Power consumption per lamp: 40 watts (W)
- Total lamps: 10
- Total power consumption: [tex]\( \frac{40}{1000} \times 10 = 0.4 \)[/tex] kW

### Step 2: Calculate the total power consumption

Adding up the power consumption of all appliances:
[tex]\[ \text{Total power consumption} = 0.065 \, \text{kW} + 1.2 \, \text{kW} + 0.85 \, \text{kW} + 0.4 \, \text{kW} = 2.515 \, \text{kW} \][/tex]

### Step 3: Determine the cost per kWh

- Cost per kilowatt-hour (kWh): 15 kobo
- Conversion from kobo to Naira (since there are 100 kobo in 1 Naira): [tex]\( \frac{15 \text{ kobo}}{100} = 0.15 \text{ Naira} \)[/tex]

### Step 4: Calculate the total cost

To find the total cost, multiply the total power consumption by the cost per kWh:
[tex]\[ \text{Total cost} = 2.515 \, \text{kW} \times 0.15 \, \text{Naira/kWh} = 0.37725 \, \text{Naira} \][/tex]

Thus, the cost for the housekeeper to switch on all the appliances simultaneously is approximately 0.37725 Naira.

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