Answer
The purchase price is \$120.
The total price including tax is \$130.20.
Work Step by Step
a) sales tax=tax rate * price
$10.20=8.5\% \times p$
$10.20=0.085\times p$
$10.20\div0.085=0.085p\div0.085$
$120=p$
b) total price = purchase price + sales tax
$t=120+10.20=130.20$
