Alligation or Mixture problems
From a vessel filled with alcohol 1/5 of its contents is removed and the vessel is then filled up with water. If this be done 5 times in succession, what proportion of the alcohol originally contained in the vessel will have been removed from it?
Using Alligation rule, (Quantity of cheaper tea) / (Quantity of dearer tea) = (d - m) / (m - c) = 7/3Therefore, they must be mixed in the ratio of 7 : 3.