Question 22596
Let "x" be the amount of 30% solution.
Then "50-x" is the amount of 80% solution.

Equation:
Amt. of alcohol in 30% + Amt. in 80% = Amt. in 60%
 30x +80(50-x) = 60(50)
 30x +4000 - 80x =3000
          -50x = -1000
             x = 20 mm of 30% solution
          50-x = 30 mm of 80% solution

Cheers,
Stan H.