The mass of a 30% solution of baking soda is 700 g. How many grams of water do you need

The mass of a 30% solution of baking soda is 700 g. How many grams of water do you need to add to make a 20% solution?

To solve this problem, we introduce a conditional variable “X”, through which we denote the amount of water that must be added to the food salt solution. The first step is to determine the amount of baking soda in the baking soda solution. As a result, we get a mass of soda equal to (30% x 700) / 100% = 210 grams. Now, based on the data of the problem, we will compose the following equation: (210 x 100%) / (700 + X) = 20%. Solving this equation, we get X equal to 350 grams of soda.
Answer: 350 grams of baking soda must be added to the baking soda solution.