How much salt and water do you need to take to prepare 150 g of a 3% solution?

To solve this problem, you must use the following formula and make up the proportion:

Where 100% is the entire solution, the mass of which is 150 grams, and 3% is the amount of required salt.

100% * 150 = 3% * x.

w = m (substance) * 100% / m (solution)
We deduce: m (substance) = w * m (solution) / 100%

Since we need to get 150 grams of a 3 percent solution, we substitute the data into the formula:

m (substance) = 3% * 150g / 100% = 4.5 g

Answer
In order to get a 3% solution, we need to take 4.5 grams of salt.

Then all substances in the following proportion:
150g-4.5g = 145.5g water