You can buy 20 fluid ounces of shampoo for $4.40 or 24 fluid ounces for $4.80. Which is the better buy? Explain.

Ok, so you put $4.40 over 20 ounces which will get you $ 0.22 per ounce

You do the same for the other one.

4.80 over 24 ounces which is $ 0.20 per ounce

So the better price would be 24 fluid ounces of shampoo for $ 4.80

First you have to do 440 / 20, which is 22 cents per bottle

Next you have to do 480 / 24, which is 20 cents per bottle

20 < 22, so the 24 ounces of shampoo is the correct answer.