Question

To calculate the cost of two phone calls, in cents, the following expression was used:

how to caculate the cost

Answer 1

To calculate the cost of two phone calls in cents, you need to know the rate per minute for each call, as well as the duration of each call in minutes. The general formula to calculate the total cost is:

\[
\text{Total Cost} = (\text{Rate per minute for Call 1} \times \text{Duration of Call 1}) + (\text{Rate per minute for Call 2} \times \text{Duration of Call 2})
\]

Here’s how to break it down step by step:

1. **Determine the rates and durations**:
- Let \( r_1 \) be the rate per minute for the first call (in cents).
- Let \( d_1 \) be the duration of the first call (in minutes).
- Let \( r_2 \) be the rate per minute for the second call (in cents).
- Let \( d_2 \) be the duration of the second call (in minutes).

2. **Calculate the cost for each call**:
- Cost for Call 1 = \( r_1 \times d_1 \)
- Cost for Call 2 = \( r_2 \times d_2 \)

3. **Add the costs to get the total cost**:
\[
\text{Total Cost} = (r_1 \times d_1) + (r_2 \times d_2)
\]

4. **Example**:
- If Call 1 costs 30 cents per minute and lasts 5 minutes, and Call 2 costs 20 cents per minute and lasts 10 minutes, the calculation would be:
- Cost for Call 1 = \( 30 \, \text{cents/min} \times 5 \, \text{min} = 150 \, \text{cents} \)
- Cost for Call 2 = \( 20 \, \text{cents/min} \times 10 \, \text{min} = 200 \, \text{cents} \)
- Total Cost = \( 150 + 200 = 350 \, \text{cents} \)

This gives you the total cost of the two phone calls in cents.