Kopano needs to upgrade his cell phone contract and has two options: Business contract or Prepaid option. Given the rates, calculate the cost of using the phone for 300 minutes per month for each option and identify variables and relationships for graphing.

Here are the answers to your questions:

3.1.1

One advantage of using the prepaid option is that there is no monthly subscription fee. This allows for better control over spending as you only pay for what you use.

3.1.2

The monthly subscription fee for the business contract is R120 per month.

3.1.3

Let $m$ be the number of minutes used. Total Cost (R) = Monthly subscription + (Peak time call rate $\times$ Number of minutes) $Total Cost (R) = 120 + 1.50m$ The formula is: $\text{Total Cost (R) = 120 + 1.50m}$

3.1.4

To calculate the cost for 300 minutes using the business contract, substitute $m = 300$ into the formula from 3.1.3.

The cost of using the phone for 300 minutes per month with the business contract is R570.

3.1.5

• Dependent variable: Total Cost (R) • Independent variable: Number of minutes used

3.1.6

The type of relationship represented by the prepaid graph is a linear relationship. Reason: The cost increases at a constant rate (R2.30 per minute) with no fixed initial cost, meaning the graph will be a straight line passing through the origin.

3.1.7

I cannot draw a graph as this is a text-based interface. However, the equation for the business contract line to be drawn on the same axes would be: $C = 120 + 1.50m$ where $C$ is the total cost and $m$ is the number of minutes.