Question

To 15 litres of water containing 20% alcohol, we add 5 litres of pure water. what is the % of alcohol?

Answer 1

The amount of alcohol in 15 litres.

20/100 × 15 = 3 litres

When we add 5 litres of pure alcohol.

3 + 5 = 8 litres

We now have 8 litres of alcohol in the solution.

The total amount of solution after 5 litres of solution is added is 15 + 5 = 20 litres

New percentage of alcohol is :

8/20 × 100% = 40%

Answer 2

Answer:

The answer is 15%

Explanation:

saying 20%alcohol in 15 litre solution.

It means (20/100)*15=3 litres

Now 5 litre of water is added not alcohol.

So it means only the volume of solution is increases by 5 not alcohol.

It means 15+5=20

Now % of alcohol is

(3/20)*100=15%

:)