Question

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

i got 12 lb.

Answer 1

water is 0% salt...did you use that?

Answer 2

3 lb?.

Answer 3

um i'm not sure..

Answer 4

i'll see what @Shane_B has to say...

Answer 5

There are 20 x 0.15 = 3 lbs of salt before dilution, and of course 3 lbs afterward, too. So the question becomes 3/(20 + x) = 0.12, solve for x.

Answer 6

That's right...had to think about it (it's 5:30am here :)

Answer 7

so its 12lb.

Answer 8

No, 5. 3/(20 + 5) = 3/25 = 0.12.