A milkman mixes 30 liters of water with 70 liters of milk. After selling one fourth of this mixture, he adds water to replenish the quantity that he has sold. What is the current proportion of water to milk?

A 20 liter mixture contains 30% alcohol and 70% water. If 5 liters of water is added to the mixture, what will be the percentage of alcohol in the new mixture?

A shopkeeper mixes 60 kg of sugar worth Rs. 30 per kg with 90 kg of sugar worth Rs. 40 per kg. At what rate he must sell the mixture to gain 20%?

A container has 100 litres of milk. From this container, 10 litres of milk was taken out and replaced by water. The process was further repeated twice. The volume of milk in the container after that…

In a mixture of 70 kg, the ratio of sand and cement is 4 : 1. How much sand should be added to the mixture so that the ratio of said and cement in it becomes 6 : 1?

A 60 liter mixture of milk and water contains 10% water. How much water must be added to make water 20% in the mixture?