A can contains a
mixture of two liquids A and B is the ratio 7 : 5. When 9 litres of
mixture are drawn off and the can is filled with B, the ratio of A and B
becomes 7 : 9. How many litres of liquid A was contained by the can
A milk vendor has 2 cans of milk. The first contains 25% water and the
rest milk. The second contains 50% water. How much milk should he mix
from each of the containers so as to get 12 litres of milk such that the
ratio of water to milk is 3 : 5?