<PRE><B>Question 996636</B>
How many liters of pure acid and how many liters of a 25% acid solution should be mixed to get 10 liters of a 40% acid solution? 
------
Equation:
acid + acid = acid
1*x + 0.25(10-x) = 0.40*10
------
100x + 25*10 - 25x = 40*10
------
75x = 15*10
----
x = 2 liters (amt of pure acid needed)
------------
Cheers,
Stan H.
--------------</PRE>