$49 \ kg$ of blended tea contains Assam and Darjeeling tea in the ratio $5:2$. The quantity of Darjeeling tea to be added to the mixture to make the ratio of Assam to Darjeeling tea $2:1$ is..........$kg$.

In two types of brass,the ratios of Copper to Zinc are $8:3$ and $15:7$ respectively. If the two types of brass are melted and mixed in the ratio $5:2$,a new type of brass is obtained. The ratio of Copper to Zinc in this new type of brass is:

In what ratio must sugar at $Rs. 2$ per $kg$ be mixed with sugar at $Rs. 3.50$ per $kg$ so that the mixture is worth $Rs. 2.50$ per $kg$?

Mira's expenditure and savings are in the ratio $3: 2$. Her income increases by $10 \%$. Her expenditure also increases by $12 \%$. By how many $\%$ does her saving increase?

The average monthly salary of employees,consisting of officers and workers of an organization,is ₹$3000$. The average salary of an officer is ₹$10000$ while that of a worker is ₹$2000$ per month. If there are a total of $400$ employees in the organization,find out the number of officers and workers separately.

In a laboratory,two bottles contain a mixture of acid and water in the ratio $2:5$ in the first bottle and $7:3$ in the second. The ratio in which the contents of these two bottles should be mixed such that the new mixture has acid and water in the ratio $2:3$ is