Percentage Discount given an Original Price of $360 and a Sale Price of $90

Discount Rate = 1 –  
Discount Rate = 1 – 0.25
Discount Rate = 0.75
0.75 Converted to a Percent: 0.75 = 75%
Percentage Discount given an Original Price of $360 and a Sale Price of $90 = 75%
Note: Reduction in Price = $360 – $90 = $270