The ratio of the age of Tina and Rakesh is $9:10$. $10 \text{ years}$ ago,the ratio of their ages was $4:5$. What is the present age of Rakesh (in $\text{years}$)?

$7$ years ago,the ages (in years) of $A$ and $B$ were in the ratio $4:5$; and $7$ years hence they will be in the ratio $5:6$. The present age of $B$ is (in years):

The sum of the ages of two brothers, having a difference of $8 \, \text{years}$ between them, will double after $10 \, \text{years}$. What is the ratio of the age of the younger brother to that of the elder brother?

The ratio between the ages of a father and a son at present is $5:2$. $4$ years hence,the ratio between the ages of the son and his mother will be $1:2$. What is the ratio between the present ages of the father and the mother?

If the present age of $X$ is half that of $Y$ and after $20$ years the age of $Y$ will be $1 \frac{1}{2}$ times that of $X$,what is the present age of $X$?

The ages of $A, B$ and $C$ together is $185$ years. $B$ is twice as old as $A$ and $C$ is $17$ years older than $A$. Then,the respective ages of $A, B$ and $C$ are (in years):