Concentration of alcohol in 1 st jar = 40% Concentration of alcohol in 2nd jar = 19% After the mixing, concentration of alcohol in the mixture = 26% By rule of alligation,
Hence ratio of 1 st and 2nd quantities = 7 :1 4 = 1 :2 i.e., 2/(1+ 2) = 2/3 part of the whisky is replaced.