Since, no amount was given.
Finding original price using discount price and discount rate
Original price = Discount price divide by discount rate
Assuming Discount price is 20 and discount is 0.75
Original price = 20 / 0.75
Original price = 26.67
Sales price = Original price times net of 100% and sales discount in percentage
Assuming Original price is 100 ; 15% discount
Sales price = 100 x (1 - 0.15) = 100 x 0.85 = 85
or
Sales price = Original Price minus Original price times discount
= 100 - (100 x 0.15)
= 100 - 15
Sales price = 85