Question 633450
  <pre><font face = "Tohoma" size = 3 color = "indigo"><b> 
Hi,
Let x represent the amount of 15% juice
   juice = juice
 .15x ++ .08(14-x) = .10*14L
        .07x = .02*14L
           x = .02*14L/.07
           x = 4L, amt of 15%.  Will take 10L of the 8%
and...
  {{{ .6 + .8 = 1.4}}}   Note: 1.4L being the amount of actual juice

Note if Decimals bother You, may multply thru by 100 first, if You like:
    15x + 8(14-x) = 140
           7x =  28, x = 4