Question 1090267
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According to the condition,  25 liters of this blended juice must contain  5 equal volumes of the mango juice  plus 
4  equal volumes of the orange juice  plus  1  (equal)  volume of distilled water.


In all,  there are 5 + 4 + 1 = 10 equal volumes,  each of  {{{25/10}}} = 2.5  liters.


So,  the blended juice must contain  4*2.5 = 10  liters  of orange juice.



Solved.