How much water do you need to take to prepare 120 g of a 15% saline solution?

1. Find the mass of salt required to prepare 120g of 15% salt solution. To do this, we will compose and solve the proportion:

120 g – 100%;

Xg – 15%.

X = (120 * 15): 100 = 18 (g).

2. Find the mass of water, for this we subtract the mass of salt from the total mass of the solution:

120 – 18 = 102 (g).

Answer: 102 g of water is needed to prepare the solution