Question

At Noise Pollution Cellular, plan A is $30.00 per month and $5.00 for every gigabyte of data. Plan B is $50.00 per month and $2.00 for every gigabyte of data used. Irfan wants to find out which plan is the best choice for him. On average, he uses five to eight GB of data per month.
Write an equation for each plan with monthly data, D, and total cost, C.

Answer 1

First we define variables.We have then:D: monthly data.C: total cost.
For Plan A:
 C = 5D +30
 D: [5, 8]
 We evaluate for D = 8
 C = 5 (8) +30
 C = 40 + 30
 C = 70 $
 For Plan B:
 C = 2D +50
 D: [5, 8]
 We evaluate for D = 8
 C = 2 (8) +50
 C = 16 + 50
 C = 66 $
 Answer:
 the best choice for him is plan B:
 C = 2D +50