A jar full of whisky contains 40% alcohol. A part of this whisky is replaced by another whisky containing 19% alcohol, and the percentage of alcohol becomes 26%. What part of the whisky was replaced?
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → \(\frac{2}{3}\)
After the replacement, the jar holds the 40% whisky that was kept and the 19% whisky that was put in. By alligation, the two parts are in the inverse ratio of their distances from the mean 26%.
Kept (40%) \(\propto 26-19=7\)
New (19%) \(\propto 40-26=14\)
Kept : new \(=7:14=1:2\)
Part replaced \(\displaystyle =\frac{2}{1+2}=\frac{2}{3}\)
\(\frac{2}{3}\) of the whisky was replaced.