In the given questions, two quantities are given, one as ‘Quantity I’ and another as ‘Quantity II’. You have to determine relationship between two quantities and choose the appropriate option: Quantity I: A mixes milk and sugar in an empty container in the ratio of 4: 9, respectively. If 39 litres of mixtures is taken out and 4 litres of sugar is mixed, then the ratio of milk and sugar becomes 3: 7, respectively. Find the amount of milk mixed initially. Quantity II: A tank contains mixture of water and alcohol in the ratio of 3: 7, respectively. 40 litres of mixture is sold and 4 litres of alcohol is mixed in the container. If the ratio of water and alcohol in container becomes 2: 5, then find the difference between the amount of water and alcohol present in the container initially.