Question

A cell phone company charges a flat fee plus an additional charge per minute. If the graph contains the points (0,15)
and (50,90)
, what is the fee the company charges per minute? Give your answer in exact change.(1 point)
The charge per minute is $

Answer 1

To find the charge per minute, we can analyze the information given with the two points on the graph: (0, 15) and (50, 90).

1. The point (0, 15) indicates that when no minutes are used (x = 0), the total charge is $15. This means that the flat fee is $15.

2. The point (50, 90) indicates that when 50 minutes are used, the total charge is $90.

We can set up an equation for the total charge based on minutes used:

\[
\text{Total Charge} = \text{Flat Fee} + (\text{Charge per Minute}) \times (\text{Minutes Used})
\]

Let \( m \) be the charge per minute. Using the points:

From the first point (0, 15):
\[
15 = 15 + m \cdot 0 \quad \text{(which is true)}
\]

From the second point (50, 90):
\[
90 = 15 + m \cdot 50
\]

Now, let's solve for \( m \):
\[
90 - 15 = m \cdot 50
\]
\[
75 = 50m
\]
\[
m = \frac{75}{50} = \frac{15}{10} = \frac{3}{2} = 1.5
\]

Thus, the charge per minute is:

\[
\text{The charge per minute is } \$1.50.
\]

You can also express this in terms of exact change as $1.50 if needed, or say it is 1 dollar and 50 cents.