Mathematics · Ratio and Proportion

Two containers, A and B, are filled with mixtures of milk and water. Container A holds 150 liters with a milk to water ratio of 4 : 1. Container B holds 100 liters with a milk to water ratio of 1 : 4. A specific quantity of the mixture is poured from container A into container B. As a result, the ratio of milk and water in container B becomes 1 : 1. What was the volume (in liters) of the mixture transferred from A to B?