Question

A container has 20% alcohol solution while other has 60 % alcohol solution. How many

litres of each solution must be mixed to prepare 12 litres of 50% alcohol solution?

(use two variables)​

Answer 1

Step-by-step explanation: Let us assume that the concentration of Alcohol referred here is Volume Percent.

Then,

20% alcohol means 0.2 litre of alcohol in 1 litre solution {Sol. A}

70% alcohol means 0.7 litre of alcohol in 1 litre solution {Sol. B}

60% alcohol means 0.6 litre of alcohol in 1 litre solution

The Final solution contains 50 litres of 60% alcohol. Thus, the total amount of alcohol in final solution is: 0.6*50= 30 litres

Let the amount of Sol. A added be x litres and amount of Sol. B added be 50-x litres. [50-x because total volume of solution is 50 litres]

Now equating the amounts of alcohol as:

0.2x + 0.7(50-x) = 30

=> x = 10 litres

Hence the amount of Solution A to be added is 10 litres and amount of Solution B to be added is 40 litres.