<PRE><B>Question 384814</B>
Let x=amount of water needed
Now we know that the amount of pure antifreeze before the mixture takes place (0.80*30) is equal to the amount of pure antifreeze after the mixture takes place (0.60(30+x)).  Sooo our equation to solve is:
0.80*30=0.60(30+x) simplify
24 =18+0.60x subtract 18 from each side
0.60x=6
x=10 L  amount of water needed

CK
0.80*30=0.60*40
24=24

Hope this helps---ptaylor</PRE>