LINEAR EQUATIONS

Activity 2: Cost-Effective Plans

What is a cost-effective plan?

Cost-effective plan means a plan which fulfills all the requirements of the user at minimal charges in comparison to other available plans.

This means that if a user requires to make more phone calls, then that user should choose a plan where the charges for calls are less. The same logic can be applied to other services also.

Below is the usage data of two users, Tarun and Prachi. They want to switch to a new plan which will be cheaper for them. We will look at this data and select the cheapest plan for each of them from three given tariff plans that we will present later.

Tarun

Prachi

Tariff plan used by Tarun and Prachi:

How to choose a cost-effective plan?

Classify the usage

• The usage data is classified into three parts: Category, Usage, and Usage charges.

• For each category usage information and applicable usage charges are given.

Finding the maximum usage

• For Tarun, the maximum charges are for Data (₹ 1000 )

• For Prachi, the maximum charges are for Voice Calls (₹ 400 )

Choosing suitable tariff plans

• We need to consider a tariff plan each for Tarun and Prachi in which the charges are least for the category they use the most.

• For Tarun, the suitable tariff plan will be the one with the least charge for data.

• For Prachi, it will be the one with the least charge for voice calls.

Cost-effective plan

• First, we calculate the usage charges for all the categories according to each plan and compare them.

• The plan for which the usage charges are least will be the most cost-effective plan for that user.

• We want to generalise this solution for different users. In the next section, we will show how this can be done by forming equations and drawing graphs from them.