17. You are choosing between two cellphone plans. Data Plan A has a monthly fee of $40 with a charge of $15 per gigabyte (GB). Data Plan B has a monthly fee of $30 with a charge of $20 per GB.
a. For how many GB of data will the costs for the two data plans be the same? What will be the cost for each plan?
b. If you use 6 GB of data per month, which plan is the better deal and by how much?