Don't Think Carefully
You are given \(2\) beautiful Hello-Kitty cups, filled with 100cc of milk and water respectively.
You first take 10cc of milk from the first one, and pour it into the second. Then, you take 10cc from the second, and pour it into the first.
What can you say about the first cup?
Note: You must answer the problem in less than \(30\) seconds.