Three glasses of equal volume contain acid mixed with water. The ratios of acid to water are $2:3$,$3:4$,and $4:5$ respectively. If the contents of these glasses are poured into a large vessel,what is the ratio of acid to water in the large vessel?

$A$ $20\, \text{litre}$ mixture of milk and water contains milk and water in the ratio $3:2$. $10\, \text{litres}$ of the mixture is removed and replaced with pure milk,and the operation is repeated once more. At the end of the two removals and replacements,what is the ratio of milk and water in the resultant mixture?

In three vessels,the ratio of water and milk is $6:7$,$5:9$,and $8:7$,respectively. If the mixtures of the three vessels are combined,what will be the final ratio of water to milk?

The average weekly salary per head of all employees (supervisors and labourers) is ₹ $100$. The average weekly salary per head of all the supervisors is ₹ $600$,while the average weekly salary per head of all the labourers is ₹ $75$. Find out the number of supervisors in the factory if there are $840$ labourers in it.

$A$ sugar solution of $3$ $litre$ contains $60 \%$ sugar. One litre of water is added to this solution. Then the percentage of sugar in the new solution is (in $\%$)

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 ₹):