Raj is deciding between two cell phone plans, A and B, which are both linear functions. The monthly charge for plan A according to the number of minutes used is shown in the table.

Question

Monthly Charge for Plan A

Minutes used, x

Monthly charge ($), y

0

14.45

3

14.84

6

15.23

9

15.62

12

16.01



Plan B has the same monthly base charge as plan A, but it charges a different amount per minute used. If the total monthly charge for plan B is $22.10 when 45 minutes are used, what is the slope of the linear function that represents the cost of plan B?

Answer 1

the monthly charge for A is clearly 14.45 (0 minutes)

So, for B, $(22.10-14.45)/45min = $0.17/min

Answer 2

So B s correct answer?

Answer 3

Raj is deciding between two cell phone plans, A and B, which are both linear functions. The monthly charge for plan A according to the number of minutes used is shown in the table.

Monthly Charge for Plan A
Minutes used, x
Monthly charge ($), y
0
14.45
3
14.84
6
15.23
9
15.62
12
16.01

Plan B has the same monthly base charge as plan A, but it charges a different amount per minute used. If the total monthly charge for plan B is $22.10 when 45 minutes are used, what is the slope of the linear function that represents the cost of plan B?
0.13
0.17
0.39
0.45