Tank A contains 10 liters of water. If two-fifths of this water is poured into container B, then the amount of water

Tank A contains 10 liters of water. If two-fifths of this water is poured into container B, then the amount of water in both containers will become equal. How much water was in tank B initially.

Let us express the volume of liquid in container B, for which we take the variable v.

Then, in accordance with the available data from the condition of our task, we can represent the new volume of liquid in this container in the form (v + 10 * 2/5) = (v + 4).

Since we know that after this the volume of water in both containers will equalize, then we are able to write down the equation and determine what volume of liquid was in the container B initially:

10 – 4 = v + 4;

v + 4 = 6;

v = 2.

Answer: Originally it had 2 liters.