What is the answer for this question?

Question

For the following exercises, use this scenario: A wireless carrier offers the following plans that a person is considering. The Family Plan: $90 monthly fee, unlimited talk and text on up to 8 lines, and data charges of $40 for each device for up to 2 GB of data per device. The Mobile Share Plan: $120 monthly fee for up to 10 devices, unlimited talk and text for all the lines, and data charges of $35 for each device up to a shared total of 10 GB of data. Use

Question: If a family has 3 smart phones, which plan should they choose?

Answer 1

So much extraneous information.

This is all that matters:

F $90 $40 for each device

M $120 $35 for each device

Family is $90 plus $120

Mobile is $120 plus $105

Which is a cheaper plan?