A jar full of whisky contains 40 % alcohol. A part of this whisky is replaced by another containing 9 % alcohol and now the percentage of alcohol was found to be 18%. The quantity of whisky replaced is:

\[\frac{3}{4}\] \[\frac{4}{3}\] \[\frac{2}{5}\] \[\frac{5}{2}\]

\[\frac{3}{4}\]

Let C = 40% , D = 9% and M = 18% Then the quantity is (M-D)/(C-M)