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 trader sells $10$ litres of a mixture of paints $A$ and $B$, where the amount of $B$ in the mixture does not exceed that of $A$. The cost of paint A per litre is Rs. $8$ more than that of paint B. If the trader sells the entire mixture for Rs. $264$ and makes a profit of $10 \%$, then the highest possible cost of paint B, in Rs. per litre, is

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