In what ratio should coffee powder costing ₹ $2500$ per $kg$ be mixed with coffee powder costing ₹ $1500$ per $kg$ so that the cost of the mixture is ₹ $2250$ per $kg$?

In what ratio must $25 \%$ hydrochloric acid be mixed with $60 \%$ hydrochloric acid to get a mixture of $40 \%$ hydrochloric acid?

In what ratio should sugar at ₹ $30$ per $kg$ be mixed with sugar at ₹ $45$ per $kg$ so that on selling the mixture at ₹ $42$ per $kg$ there is a profit of $20 \%$?

The cost of Type $1$ rice is ₹ $15/kg$ and Type $2$ rice is ₹ $20/kg$. 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 ₹):

Two casks of $48$ $litres$ and $42$ $litres$ are filled with mixtures of wine and water,the proportions in the two casks being respectively $13:7$ and $18:17$. If the contents of the two casks are mixed,and $20$ $litres$ of water is added to the whole,what will be the proportion of wine to water in the resultant mixture?

In a $120$ $litre$ mixture of milk and water,water is only $25 \%$. The milkman sold $20$ $litre$ of this mixture and then added $16.2$ $litre$ of pure milk and $3.8$ $litre$ of pure water to the remaining mixture. What is the percentage of water in the final mixture (in $\%$)?