Question

a 32 ounce bottle of apple juice for 2.50$ or a 48 ounce bottle of 3.84$ which is the better deal

Answer 1

Simple division problem:

$2.50/32 oz 
versus
$3.84/48 oz

Use a calculator:
$0.078125 per oz
versus
$0.08 per oz

So $2.50 for a 32 ounce bottle is better because it is less than 8 cents per ounce which is how much the other cost.