There are three vessels P, Q and R, Vessel P and Q filled with mixture of milk and Water in the ratio of 5: 4 and 5: 3 respectively. 25% of mixture from vessel P taken out and mixed in vessel R, which contains 45 L pure milk. If in resulting mixture milk is 250% more than water in vessel R and initial quantity of mixture in vessel Q is 20 l less than that of mixture in vessel P, then find the quantity of milk in vessel Q?