How do you make a 3 percent solution from a 40 percent solution?

Answer 1

This depends on the volume of the 40 percent solution you have. The question can be rewritten as:

40%a/(a+b) = 3% where a is the volume of the 40% solution, and b is the volume of water we need to add. Multiply both sides by (a+b) to get:

40%a = 3%a + 3%b

Subtract 3%a from both sides to get

37%a = 3%b

Divide by 3% to get:

12.3333...a = b

Thus whatever the current volume is, you need to add 12.33333 times that volume in water in order to get a 3% solution.