Math Problem : CC.1 Water and wine in two vessels

There are two vessels, A and B, the water of 1L is contained in A, and the wine of 1L is contained in B.

After having taken out the water of 1dL from A into B and stirring enough, the mixed-solution of 1dL was returned to A from B.

Is there more amount of the water in B than the amount of the wine in A or less or same ?

Answer

Same

Solution

The amount of the liquid in A and B is not changed at the beginning and the last. 

Therefore, since the wine of the same amount as the water mixed into B is contained in A, it is an equivalent amount. 

There is 10/11 dL of water in A and 10/11 dL of wine in B.