Using percentages for expressing discounts and comparing prices

Method 2

100% − 20% = 80%.

Therefore the new sale price will be 80% of the original price.

Sale price for the first pair = 0.8 × $95
  = $76.

100% − 25% = 75% therefore the new sale price will be 75% of the original price.

Sale price for the second pair = 0.75 × $90
  = $67.50.

The difference between the sale prices is = $76 − $67.50 = $8.50.