Marks of $X$ and $Y$ are in the ratio $3: 11$ respectively. If the marks of $X$ are $9$,then find the marks of $Y$.

Three vessels having volumes in the ratio of $2: 3: 5$ are full of a mixture of water and milk. In the first vessel,the ratio of water and milk is $1: 3$,in the second $2: 3$,and in the third vessel,$2: 5$. If all the three vessels are poured into a large container,what is the resulting ratio of milk and water?

If $P: Q: R = 2: 3: 4,$ then find $\frac{P}{Q}: \frac{Q}{R}: \frac{R}{P} ?$

$A$ person's present age is two-fifth of the age of his mother. After $8$ years,he will be one-half of the age of his mother. How old is the mother at present (in $years$)?

In a bag,there are coins of $25 p$,$10 p$,and $5 p$ in the ratio of $2:3:4$. If there is $Rs. 50$ in all,how many $5 p$ coins are there?

Two numbers are in the ratio $3: 5$. If each number is increased by $10$,the ratio becomes $5: 7$. The numbers are: