The answer would be $15.20 because you'd have to divide 12 dollars by 64 to get how much its cost for 1 ounce. So when you do that, you get 0.1875. Since this is money, we round it up to the nearest hundredth. So it's $0.19. Then you multiply 0.19 by 80 to get $15.20. So that's how much an 80 oz. Bottle costs.