SOLUTION: A distributor has two gasohol blends: one that contains 5.00% alcohol and another with 11.0% alcohol. How many litres of each must be mixed to make 428 L of gasohol containing 9.50

alcohol + alcohol      = alcohol


0.05x   + 0.11*(428-x) = 0.095*428


0.05x + 0.11*428 - 0.11*x = 0.095*428


-0.06x = 0.095*428 - 0.11*428


-0.06x = -0.015*428  ====>  x =  = 107.


Answer.  107 liters of the 5% gasohol  and 428-107 = 321 liter of the 11% gasohol.


Check.  0.05*107 + 0.11*321 = 40.66 liters of pure alcohol;

        0.095*428 = 40.66 liters of pure alcohol.    ! Correct !