CAT (QA) PYQs

A mixture P is formed by removing a certain amount of coffee from a coffee jar and replacing the same amount with cocoa powder. The same amount is again removed from mixture $P$ and replaced with same amount of cocoa powder to form a new mixture $Q$. If the ratio of coffee and cocoa in the mixture $Q$ is $16: 9$, then the ratio of cocoa in mixture $P$ to that in mixture $Q$ is

A glass contains $500 \mathrm{cc}$ of milk and a cup contains $500 \mathrm{cc}$ of water. From the glass, $150 \mathrm{cc}$ of milk is transferred to the cup and mixed thoroughly. Next, $150 \mathrm{cc}$ of this mixture is transferred from the cup to the glass. Now, the amount of water in the glass and the amount of milk in the cup are in the ratio

A jar contains a mixture of $175 \mathrm{ml}$ water and $700 \mathrm{ml}$ 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