A vessel contains 60 litres of milk. 12 litres of milk taken out from it and replaced with water. Then again form mixture, 12 litres is taken out and replaced with water. The ratio of milk and water in the resultant mixture is :

In what proportion must a grocer mix sugar at Rs. 12 a kg and Rs. 7 a   kg Sugar as to make a mixture worth Rs 8. a kg?

Two casks of 48 liter and 42 liter are filled with mixtures of milk and water, the proportions in the two casks being respectively 13 : 7 and 18 : 17. If the contents of two casks be mixed and 20 liter of water be added to the whole , what will be the proportion of milk and water in the resulting mixture ?

An alloy contains copper and tin in the ratio 3: 2. If 250 gm of copper is added to this alloy then copper in it becomes double the quantity of tin in it. What is the amount (in gm) of tin in the alloy? 

Gold is 19 times as heavy as water and copper is 9 times as heavy as water. In what ratio should these metals be mixed so that the mixture may be 15 times as heavy as water?

A shopkeeper bought 15 kg of rice at the rate of Rs.29 per kg and 25 kg of rice at the rate of Rs.20 per kg. He sold the mixture of both types of rice at the rate of Rs. 27 per kg. his profit in this transaction is___

A mixture of 40 liters of milk and water contains 30% water. How much milk should be added to this mixture so that the new mixture contains 80% milk?

How many kilogram of rice costing Rs.60 per kg must be mixed with 24 kg of rice costing Rs.42 per kg so that there may be a gain of 12% by selling the mixture at Rs.56 per kg?