A container is full of a mixture of alcohol and water. The ratio of alcohol to water in the mixture is 1 : 4. If some amount of mixture is taken out and it is filled with water then the ratio of alcohol to water becomes 1 : 9. If the size of a container is 10litre then how much water is added into the mixture?
1
4 litre
2
9 litre`
3
7 litre
4
5 litre
5
6 litre