Question : A mixture of acid and water contains 20% acid. When 10 litres of water is added to the mixture, then the percentage of acid becomes 15%. What is the original quantity of the mixture?

Option 1: 30 litres

Option 2: 25 litres

Option 3: 40 litres

Option 4: 35 litres

Question : If solution A contains 10% acid and solution B contains 30% acid, what ratio of solution A to solution B should be mixed to obtain a mixture with 25% acid?

Option 1: 1 : 2

Option 2: 3 : 1

Option 3: 1 :  3

Option 4: 2 : 1

Question : A vessel contains 20 L of acid. 4 L of acid is taken out of the vessel and replaced by the same quantity of water. Next, 4 L of the mixture is withdrawn and again the vessel is filled with the same quantity of water. The ratio of the quantity of acid left in the vessel with the quantity of acid initially in the vessel is:

Option 1: 4 : 5

Option 2: 4 : 25

Option 3: 16 : 25

Option 4: 1 : 5

Question : A 40 litres mixture contains 25% alcohol and 75% water. If 10 litres of water are added to the mixture, the percentage of alcohol in the new mixture is:

Option 1: 27%

Option 2: 18%

Option 3: 20%

Option 4: 25%

Question : A mixture contains milk and water in a ratio of 5 : 3, respectively. On adding 7 litres of water, the ratio of milk to water becomes 1 : 2. Find the quantity of milk in the mixture.

Option 1: 7 litres

Option 2: 10 litres

Option 3: 5 litres

Option 4: 3 litres