How much water should you add to 50 liters of 96% alcohol to get 80% alcohol?

1. Determine how many liters of alcohol are in the solution. We take this quantity as a and make up the proportion:

50 l – 100%, and l – 96%;

50: a = 100: 96;

a = (50 x 96): 100;

a = 48 l;

2. Determine the volume of the new solution. We take it for a and make up the proportion:

48 l – 80%, and l – 100%;

48: a = 80: 100;

a = (48 x 100): 80;

a = 60 l;

3. Determine the amount of water in the new solution:

60 – 48 = 12 liters;

4. Determine the amount of water in the initial solution:

50 – 48 = 2 l;

5. Determine how much water needs to be added to the solution:

12 – 2 = 10 liters.

Answer: 10 liters of water must be added to the solution.