Answer:
$2.25
Step-by-step explanation:
Let c represent the cost of a cup of coffee. Then the total amount paid for 3 cups is ...
3c + 3c·0.08 = 7.29
3.24c = 7.29
c = 7.29/3.24 = 2.25
A cup of coffee costs $2.25.
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Comment on "I will give you 100 pointd"
I don't know what a "pointd" is, but I suggest you not make promises you cannot keep.