The answer is the 16 - ounce bottle of shampoo for $7. This is how I did it:
I divided the price and the ounce of shampoo in the bottle.
[tex]24/9 = $2.67 per ounce[/tex] and [tex]16/7 = $2.29 per ounce[/tex]
Now you can see which one is a cheaper price. Hope this helped you =)
