The ratio between Sumit's and Prakash's age at present is $2:3$. Sumit is $6 \text{ yr}$ younger than Prakash. What will be the ratio of Sumit's age to Prakash's age after $6 \text{ yr}$?

What is the value of $68 \%$ of two-fifths of $550$?

The ratio of three numbers is $2: 3: 5$. If the sum of the three numbers is $275$,then what is the largest among the three numbers?

There is $1000 \, \text{litres}$ of milk in a pot. $100 \, \text{litres}$ of milk is taken out and the same amount of water is poured into it. Again, $200 \, \text{litres}$ of the mixture is taken out and the same amount of water is poured into it, and finally, $400 \, \text{litres}$ of the mixture is taken out and the same amount of water is poured into it. What is the amount of milk in the resulting mixture?

Three numbers $A, B$ and $C$ are in the ratio $12: 15: 25$. If the sum of these numbers is $364$,find the ratio between the difference of $B$ and $A$ and the difference of $C$ and $B$.

Two numbers are in the ratio $5:3$. If $9$ is subtracted from each,the new ratio becomes $9:5$. What are the two numbers?