The cost of Type $1$ rice is $Rs. 15$ per $kg$ and Type $2$ rice is $Rs. 20$ per $kg$. If both Type $1$ and Type $2$ are mixed in the ratio of $2:3$,then the price per $kg$ of the mixed variety of rice is? (in $Rs.$)

Two liquids are mixed in the ratio of $3: 2$ and the mixture is sold at $Rs. 11$ per litre at a $10 \%$ profit. If the $1$st liquid costs $Rs. 2$ more per litre than the second,what is the cost per litre of the second liquid (in $.80$)? (in $Rs.$)

In what proportion must a grocer mix sugar at ₹ $12$ per $kg$ and ₹ $7$ per $kg$ so as to make a mixture worth ₹ $8$ per $kg$?

In what ratio must water be added to spirit to gain $10 \%$ by selling it at the cost price?

In what ratio must a person mix three kinds of tea costing $Rs. 60$ per $kg$,$Rs. 75$ per $kg$,and $Rs. 100$ per $kg$ so that the resultant mixture when sold at $Rs. 96$ per $kg$ yields a profit of $20\%$?

$A$ bottle contains $81$ litres of pure milk. $\frac{1}{3}$ of the milk is replaced by the same amount of water. Again,$\frac{1}{3}$ of the mixture is replaced by the same amount of water. The ratio of the milk and water in the new mixture is