Question 650872
Let x=amount of 30% solution needed
Now we know that the amount of pure alcohol that exists before the mixture takes place (0.30x+0.80*50) has to equal the amount of pure alcohol that exists after the mixture takes place (0.60(50+x)).
Soooo:
0.30x+0.80*50=0.60(50+x)  simplify
0.30x+40=30+0.60x  or
0.60x-0.30x=40-30
0.30x=10
x=33.333 ounces---amount of 30% alcohol solution needed
CK
0.30*(33 1/3)+40=30+0.60*(33 1/3)
0.30(100/3)+40=30+0.60(100/3)
10+40=30+20
50=50
Hope this helps---ptaylor