CAT (QA) PYQs

A solution, of volume $40$ litres, has dye and water in the proportion $2: 3$. Water is added to the solution to change this proportion to $2: 5$. If one-fourths of this diluted solution is taken out, how many litres of dye must be added to the remaining solution to bring the proportion back to $2: 3$?

A glass is filled with milk. Two-thirds of its content is poured out and replaced with water. If this process of pouring out two-thirds the content and replacing with water is repeated three more times, then the final ratio of milk to water in the glass, is

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