The cereal that costs more per ounce is the cereal that is being sold at $3.09 for 13.5 ounces.
= Cost / Number of ounces
= 3.09 / 13.5
= $0.23 per ounce
= Cost / Number of ounces
= 3.99 / 20
= $0.20 per ounce
In conclusion, the first cereal costs more.
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