A jar full of whisky contains 40% of alcohol.A part of this whisky is replaced by anotherwhisky containing 19% alcohol and now thepercentage of alcohol becomes 26%. The partof whisky replaced was?

\(\frac{2 }{3}\)

Ratio of alcohol to whiskey in the jar = 40 : 60 = 2 : 3.

Ratio of alcohol to whiskey in the new mixture

=26 : 74

=13 : 37

Now, applying the given allegation method, we have

∴ Ratio of alcohol to whisky in the replaced mixture

=\(\frac{7}{100}\) : \(\frac{7}{50}\) = \(\frac{1}{2}\)

∴ Quantity of whisky replaced = \(\frac{2}{2 + 1}\) = \(\frac{2}{3}\)