From 60% and 80% hydrochloric acid solutions, it is necessary to obtain 8 liters of a 75%

From 60% and 80% hydrochloric acid solutions, it is necessary to obtain 8 liters of a 75% solution. How many liters of 80% solution do you need to take?

Suppose that x liters of 80% hydrochloric acid solution are needed to prepare the required solution. This solution will contain:

x * 80: 100 = 0.8 * x liters of acid.

Therefore, a 60% solution will require (8) liters, which contain:

(8 – x) * 60: 100 = 0.6 * (8 – x) = 4.8 – 0.6 * x liters of acid.

On the other hand, 8 liters of a 75% solution contains:

8 * 75: 100 = 6 liters of acid.

Let’s compose and solve the equation:

0.8 * x + 4.8 – 0.6 * x = 6,

0.2 * x = 6 – 4.8,

x = 1.2: 0.2,

x = 6 (l) – an 80% solution is required.