A vessel contains a mixture of Grapes - Pineapple and Banana juices in the respective ratio of 4:6:5. 15 litres of this mixture is taken out and 8 litres of grape juice and 2 litres of pineapple juice is added to the vessel. If the resultant quantity of grape juice is 10 litres less than the resultant quantity of pineapple juice - what was the initial quantity of mixture in the vessel ? (in litres)