How many $kg$ of salt at $42$ $P$ per $kg$ must a man mix with $25 \, kg$ of salt at $24$ $P$ per $kg$,so that he may,on selling the mixture at $40$ $P$ per $kg$,gain $25 \%$ on the outlay?

The milk and water in two vessels $A$ and $B$ are in the ratio $4:3$ and $2:3$ respectively. In what ratio should the liquids in both the vessels be mixed to obtain a new mixture in vessel $C$ containing half milk and half water?

How many kg of sugar costing ₹ $11.70/kg$ must be mixed with $24$ $kg$ of sugar costing ₹ $8.1/kg$ so that there may be a gain of $15 \%$ by selling the mixture at ₹ $9/kg$? (in $kg$)

Tea worth ₹ $126/kg$ and ₹ $135/kg$ are mixed with a third variety in the ratio $1:1:2$. If the mixture is worth ₹ $153/kg$,the price of the third variety per kg will be (in ₹):

$A$ person has a chemical costing $Rs. 25$ per $litre$. In what ratio should water be mixed in the chemical so that by selling the mixture at $Rs. 20$ per $litre$,he may get a profit of $25\%$?

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 $Rs.$)