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Hi, Previously Posted
How much orange juice at 42¢ a liter should be mixed with grapefruit juice
 at 42¢ a liter should be mixed with grapefruit juice
 worth 32¢ a liter to make 200 liters of a mixture worth 36¢ a liter? 
  .42x + .32(200-x ) = .36· 200   |solve for x, mulitiplying 1st thru by 100 if you like