Question 659460
A chemist 80 mil of 25% chemical solution. he only has a 50% chemical solution and a 10% chemical 
-------
Equation:
active + active = active
0.50x + 0.10(80-x) = 0.25*80
----
Multiply thru by 100 to get:
50x + 10*80 - 10x = 25*80
40x = 15*80
x = 30 ml (amt. of 50% solution needed)
-------
80-x = 70 ml (amt. of 10% solution needed)
========================
Cheers,
Stan H.