Some amount of a 120 gram 16% solution was taken out and replaced with pure alcohol. The result was a solution of 30% alcohol. How many grams were taken out?
Ok so you know that 16% of 120 is 19.2, so now I'm trying to see what 19.2 is 30% of.
So I have the equation x*0.3 = 19.2, so x = 19.2/.3, which is then equal to 64.
120 - 64 = 56.
The answer is 56.