Problem: A glass contains a certain amount of water, and another glass contains exactly the same amount of wine. We remove a spoonful from the glass of wine that we put in the glass of water, and we stir this glass. Then, we remove a spoonful (with the same spoon) from the mixture glass, and put it in the glass of wine.
Is there more wine in the glass of water, or more water in the glass of wine?
Or is there the same quantity?
