So if 32 oz is 20% more than the average bottle, you multiply 32 by .20 which gives you 6.4. This means that the 32 oz bottle is 6.4 oz more than the regular bottle. Furthermore, 32 - 6.4 = 25.6 so that's how big the typical bottle is.
so you see that there's 20 percent right, you find what number u can add it by to get 100, so 80+20=100 so u do that and put it in a decimal form which is 0.8 and you multiply it by the price so 0.8 x 75= 60