Question

The amount of data left on a cell phone plan is 6 GB after 8 days. 1.5 GB of data is used each day. How much is a available at the beginning of the cycle?

Answer 1

All we have to do is add 1.5 GB per day times the 8 days that's already happened to the current 6 GB, and so it looks like this:
8(1.5)+6
12+6
18 GB at the beginning of the cycle

Answer 2

18 GB because if you multiply 1.5 by 8 then add 6 you get 18, add GB because thats the unit.