#### Answer

$35

#### Work Step by Step

Change the percent to a decimal by moving the decimal point two spaces to the left.
20%=0.2
Sale Price=Original Price-Reduction(Original Price)
S=O-RO
28=O-0.2(O)
28=O(1-0.2)
28=O(0.8)
$\frac{28}{0.8}$=O
35=O
O= $35