a.) Discount = 30%
Percent of the original price on sale = 100% - 30% = 70%
b.) Original price = $500
Discount = 30%
Dollar amount of the discount = $500 x (30% / 100%) = $500 x 0.30 = $150
c.) The sale price = $500 - (Discount Amount) = $500 - $150 = $350