Question

The cost of electricity in Sara's town is \(\$ 0.265\) per kilowatt-hour. If she uses 1050 kilowatt-hours of electricity in July, what will her electric bill be for that month? A. \(\$ 27.83\) B. \(\$ 278.25\) C. \(\$ 1,049.74\) D. \(\$ 3,962.26\)

Short answer

The correct answer is B. \( \$278.25 \).

Step-by-step solution

Identify the given values

The cost of electricity per kilowatt-hour is \( \$0.265 \) and the total kilowatt-hours used in July is 1050.

Set up the multiplication

To find the total cost, multiply the cost per kilowatt-hour by the number of kilowatt-hours used: \( 0.265 \, \text{dollars per kWh} \times 1050 \, \text{kWh} \)

Perform the multiplication

\( 0.265 \times 1050 \)= 278.25.

Determine the correct answer

From the calculation, the total cost is \( \$278.25 \). The correct answer is B. \( \$278.25 \).

Key concepts

Multiplication

When calculating costs based on usage, multiplication is a key tool. In this problem, Sara's electricity consumption needs to be multiplied by the cost per kilowatt-hour.
Multiplication involves taking two numbers and adding one of them to itself as many times as the other indicates. For example, if you have to find the total cost for 1050 kilowatt-hours (kWh) at a rate of $0.265 per kWh, you multiply these two numbers.
Write it as:
\(\text{Cost} = \text{Rate per kWh} \times \text{Total kWh}\)\(\text{Cost} = 0.265 \times 1050\)
This multiplication gives you the total cost of electricity for Sara's usage in July.

Kilowatt-hour

Kilowatt-hour (kWh) is a unit of energy. It measures the amount of electricity used over time. One kilowatt-hour is equal to using 1000 watts of power for one hour.
It's crucial to understand this unit when calculating electricity bills. For example, if Sara's household appliances consume 1000 watts consistently for an hour, that's 1 kWh. If she used appliances totaling 1050 kWh in a month, this is the value you multiply by the cost per kWh to find her bill.
Always check your appliances for their wattage and consider the time they run to estimate your monthly usage in kilowatt-hours (kWh).

Problem-solving

Solving problems like these involves a clear approach. Follow these steps for success:

• Identify the given values: Find out the cost per kWh and the total kWh used.
• Set up the equation: Use multiplication to combine these values.
• Perform the calculation: Carry out the multiplication accurately.
• Choose the correct answer: Compare your result with provided options to ensure it's correct.

By breaking down the problem and working through each step methodically, you'll reach the right solution. This method is applicable to various real-life calculations, making it an essential skill in managing expenses.