Ram mixes $80 kg$ of sugar worth $Rs 6.75$ per kg with $120 kg$ worth of $Rs 8$ per kg. At what rate shall he sell the mixture to gain $20\%$?

Two vessels, A and B, contain milk and water mixture in ratio $5:3$ and $2:3$. When these mixtures are mixed to form a new mixture containing half milk and half water, they must be taken in the ratio of:

A dishonest milkman offers to sell his milk at C.P but, he mixed it with water, and thereby, he gains $25\%$. The percentage of water in the mixture is: