Question

carly is comparing cell phone rate plans. each plan has an initial fixed charge plus a charge per 100 minutes. what is the cost per 100 minutes for the cell phone plan shown below? a. $20.00 b. $10.00 c. $90.00 d. $300.00

Explanation:

Step1: Find two points on the line

Let's take two points \((0,30)\) and \((100,40)\) from the graph.

Step2: Calculate the slope (cost per 100 minutes)

The formula for slope \(m=\frac{y_2 - y_1}{x_2 - x_1}\). Here, \(x_1 = 0,y_1=30,x_2 = 100,y_2 = 40\).
\(m=\frac{40 - 30}{100-0}=\frac{10}{100}\). The cost per 100 minutes is \(10\) dollars.

Answer:

B. \(\$10.00\)