Question

How many ml of a 30% salt solution must be mixed with a 100 ml of a 10% salt

solution to increase the salt concentration to 18%?

Answer 1

66 2/3 mL

Explanation:

Let v represent the volume in mL of added 30% solution. Then the amount of salt in the mix is ...

0.10×100 +0.30×v = 0.18(100 +v)

0.12v = 0.08(100) . . . . .subtract (0.18v +0.10×100)

v = 8/0.12 . . . . . . . . . . . divide by the coefficient of v

v = 66 2/3 . . . . mL

Adding 66 2/3 mL of 30% salt solution to 100 mL of 10% salt solution will make 166 2/3 mL of 18% salt solution.