6. product a is a 12-ounce bottle of generic mouthwash that sells for $1.15. product b is a 24-ounce bottle of mouthwash that costs $2.79. which is the better buy?

12 oz = 1.15
24 oz = 2.79
Let's see if 2x12oz is less, equal, or more than the price of the 24oz.
1.15 x 2 = 2.30
2.30<2.79
12 oz is a better buy since 2 of them are cheaper than the 24 oz.