Some water was evaporated from 400 g of a 12% solution and a 16% solution was obtained. How much water did you evaporate?
1. According to the condition of the problem, 400 grams of a 12% solution are given.
12% is 12/100 of the total substance.
So the substance was only 400 * 12/100 = 48 grams.
2. During evaporation, the amount of water decreased, but the amount of the substance remained unchanged.
Let X grams of water evaporate.
Then the weight of the solution was (400 – X) grams.
The result is 16% or 16/100 of the substance.
3. We get an equation with one unknown.
48 / (400 – X) = 16/100.
16 * (400 – X) = 48 * 100.
400 – X = 300.
X = 100 grams – water.
Answer: A total of 100 grams of water was evaporated.
One of the components of a person's success in our time is receiving modern high-quality education, mastering the knowledge, skills and abilities necessary for life in society. A person today needs to study almost all his life, mastering everything new and new, acquiring the necessary professional qualities.