CAT Quantitative Aptitude Questions | CAT Ratios, Mixtures, Alligations and Averages Questions

The question is from CAT Ratio, Mixtures and Averages. The percentage of alcohol in a resultant solution is given, how much more alcohol should be added to the initial solution? CAT exam is known to test on basics rather than high funda ideas. A range of CAT questions can be asked from Ratios and Proportions, Mixtures, Alligations and Averages. Make sure you master the topics. 2IIMs CAT questions bank provides you with CAT questions that can help you gear for CAT Exam CAT 2023.

Question 28: A mixture of 100 litres of spirit and alcohol contains 25% alcohol. How much more alcohol should be added to the mixture to increase the percentage of alcohol to 30% in the new mixture?

1. 3.33 litres
2. 4 litres
3. 5.67 litres
4. 7.14 litres

Explanatory Answer

Method of solving this CAT Question from Ratio, Mixtures and Averages: When we mix two mixtures in a particular ratio, we get a third mixture. Given the third mixture how does one find the ratio in which they were mixed.

Alcohol content in the alcohol to be added = 100%
Therefore, the allegation diagram for this problem can be drawn as:

Therefore, ratio of the mixture to alcohol = \\frac{70}{5}\\) = \\frac{14}{1}\\)
So, alcohol to be added = \\frac{100}{14}\\)

The question is "How much more alcohol should be added to the mixture to increase the percentage of alcohol to 30% in the new mixture?"

Hence, the answer is "7.14 litres".

Choice D is the correct answer.