Question

Use the four-step procedure to solve the following problem. How much water must be added to a gallon of 10% saline solution to create a 2% solution?

Answer 1

We have 1 gallon of 10% saline.
How much water (x liters of 0% saline) must be added to make a 2% saline solution?
.10 * 1 + 0x = .02 * (1 +x)
.1 = .02 + .02x
.08 = .02x
x = 4 gallons of water must be added

Answer 2

4 gallons of water should be added in 10% saline solution.

Explanation:

Let x gallon of water is added in one gallon of 10% saline solution.

Therefore total volume of 10% saline solution will become (1 + x) gallons

Since concentration of water is 0% so equation will be

0.10(1) + 0(x) = .02(1 + x)

0.10 = 0.02(1 + x)

1 + x =
`(0.10)/(0.02)`

x + 1 = 5

x = 5 - 1

x = 4 gallons

Therefore, 4 gallons of water should be added to 10% saline solution to create 2% solution.