It would be 160,000; When a number that is to the right of the number you're rounding is higher than 4, you go up and add 0's to the rest of the numbers, if it is smaller than 5 you stay the same.
Brand b is 2 cents cheaper than brand a because it is 14 cents per ounce and brand a is 16 cents per ounce you do 1.68 divided by 12 and 1.28 divided by 8
