Question 23245
Follow the columbian coffee in the blends.
Let the amount of 20% blend be "x"
Then the amount of 50% blend is "100-x"
EQUATION:
   20%(x) + 50%(100-x) = 30%(100)
    20x +5000-50x = 3000
            -30x = -2000
               x = 66 2/3 lbs. (amount of 20% blend)
          100-x  = 33 1/3 lbs. ( amount of 50% blend)

Cheers,
Stan H.