Question

Thirty pounds of a salt-water solution contains fifteen percent salt. How much water must be added to weaken the solution to ten percent salt?

Answer 1

30 pounds of the solution contain 4.5 pounds of salt (15%), to get that to 10% you would have to add 15 more pounds of water so that you have 4.5 of sale in a total of 45 pounds of salt and water solution.

Answer = add 15 pounds of water