In an aqueous salt solution weighing 200 g, 50 g of water was added. As a result, the concentration

In an aqueous salt solution weighing 200 g, 50 g of water was added. As a result, the concentration of the solution decreased by 3%. How many grams of salt is in the solution?

Let’s calculate how many grams is equal to the mass of the new saline solution:

200 + 50 = 250.

Let us express the number of grams of salt in the solution, for which we will use the variable a.

Since we know, in accordance with the data from the conditions of our task, that after adding fifty grams of water, the salt content in the solution decreased by 3%, then we have the opportunity to draw up an equation and calculate how much of it in the solution:

a / 200 – a / 250 = 3/100;

5a / 1000 – 4a / 1000 = 0.03;

a / 1000 = 0.03;

a = 30.

Answer: 30 g.