Brand A sells 24 ounces of juice for 4.32. Brand B sells 30 ounces for 5.70. Which brand has the lower price per ounce, and what is that…

Divide each price by the number of ounces. Brand A costs $\frac{4.32}{24}=0.18$ dollars per ounce. Brand B costs $\frac{5.70}{30}=0.19$ dollars per ounce. Brand A is cheaper per ounce, at $0.18, choice G. Choice H names the more expensive brand as the cheaper one, even though its unit price is correct. Choice F (Brand A at $0.16) and choice J (Brand B at $0.17) have unit prices that do not match the given totals: $24(0.16)=3.84$ and $30(0.17)=5.10$. Comparing unit rates is more reliable than comparing total prices.