Section: Mathematics Knowledge

80) How much water must be added to 1 liter of a 5% saline solution to get a 2% saline solution?

1. 1 L
2. 1.5 L
3. 2 L
4. 2.5 L

Use the equation (0.05)(1) = (0.02) x: the left side represents 5% of 1 liter; the right side represents 2% of some amount of water. From the equation, x = 2.5. Subtracting the 1 liter of water already present in the 5% solution, you will find that 1.5 liters need to be added.