 
<translate> Otu galọn bụ 1 * 128 = 128 ounce. Ya mere, ọ ga-azụta 128 / 16 = 8 nke obere karama. Nke ahụ ga-efu 8 * 3 = 24 dollar. Ya mere, ọ na-echekwa 24 - 8 = $ 16. Azịza ya bụ: 16. <eng> A gallon is 1 * 128 = 128 ounces. So he needs to buy 128 / 16 = 8 of the small bottles. That would cost 8 * 3 = 24 dollars. So he saves 24 - 8 = $16.
The answer: 16. 