A bottle contains 20 fluid ounces of lotion and sells for $5.80. The 20-fluid-ounce bottle contains 125% of the lotion in the next smallest size, which sells for $5.12. Which is the better buy? Explain.

Question

The bottle is the better buy. The -fluid ounce bottle sells for $5.80. This is $ per ounce. The next smallest size is a -fluid ounce bottle sells for $5.12. This is $ per ounce. This is per ounce than the 20-fluid ounce bottle costs. .

Answer 1

compare

5.80/20 vs 5.12/(20/1.25)

or,

since the smaller bottle contains 4/5 as much, does it cost more or less than 4/5 * 5.80 ?