Alligations and Mixtures Exercise to Practice for Competitive Exams

Rahul purchased two different kinds of alcohol. In the first mixture the ratio of alcohol to water is 3:4 and in the second mixture it  is 5:6. If he mixes the two given mixture and makes a third mixture of 18 litres in which the ratio of alcohol to water is 4:5, the quantity of first mixture (whose ratio is 3:4) is required to make the 18 litres of the third kind of mixture is:

A mixture contains wine and water in the ratio 3 : 2 and another mixture contains them in the ratio 4 : 5 . How many litres of the latter mixture must be mixed with 3 litres of the former mixture so that the resultant mixture may contain equal quantities of wine and water? 

A can contains a mixture of two liquids A and B in the ratio 7:5. When 9 litres of mixture are drained 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 initially?