Question

http://gyazo.com/a45b3f393d901713b682943b4a652ee7

Answer 1

Disregarding tax, that should be something like:
\[$68 \times .2 + 68 = 81.6\]

Answer 2

so c

Answer 3

That's what I'd put. Do you know how I did that?

Answer 4

Thank you!