Two containers contain milk and water in the ratio of 2 ∶ 1 and 3 ∶ 2 respectively. How many litres from the second container should be mixed with 15 litres from the first container so that the ratio of milk to water in the new mixture will be 5 ∶ 3?
1
25 lit
2
19 lit
3
21 lit
4
30 lit