CAT 2018 Slot 2 QA Question & Solution
ArithmeticMedium
Question
A jar contains a mixture of 175 ml water and 700 ml alcohol. Gopal takes out 10% of the mixture and substitutes it by water of the same amount. The process is repeated once again. The percentage of water in the mixture is now
Options
30.3
35.2
25.4
20.5
Solution
Final quantity of alcohol in the mixture = $\dfrac{700}{700+175}*(\dfrac{90}{100})^2*[700+175]$ = 567 ml
Therefore, final quantity of water in the mixture = 875 - 567 = 308 ml
Hence, we can say that the percentage of water in the mixture = $\dfrac{308}{875}\times 100$ = 35.2 %