Question 324803
first method 

      let liter of 35%solution=x
          liter of 50% solution= 10-x

             35%x+50%(10-x)=40%10
            
            35x+500-50x=400
            100=15x
   
             x=100/15 at 35%
     
            10-100/15=50/100 at 50%
     

second method



     35%       50%
 

      40%


50-40=10  and 40-35=5



ratio=2:1======2x+1x=3x

              ans 2x=20/3
                   1x=10/3

    3x=10
     x=10/3