algebra word problem

Question

How many milliliters of vinegar must be added to 20 milliliters of a 10%-vinegar solution to make it a 25%-vinegar solution?

Answer 1

If the other vinegar is pure vinegar that means that it would be 100% concentration. That means that the expression you can set up to model this situation is

0.10(20) + 1.00(x) = 0.25 * (20 + x)

Solving that for the value of x yields

2 + x = 5 + 0.25x

0.75x = 3

x = 4

so you would need to add 4 mL of pure vinegar to get this to balance out

I hope that helps! Feel free to reach out via message for a lesson if you have any additional questions beyond that! :)