The ratio of the earnings of $A$ and $B$ is $4:7$. If the earnings of $A$ increase by $50\%$ and those of $B$ decrease by $25\%$,the new ratio of their earnings becomes $8:7$. What are $A$'s earnings (in $Rs.$)?

In an army selection process,the ratio of selected to unselected candidates was $4:1$. If $90$ less had applied and $20$ less were selected,the ratio of selected to unselected candidates would have been $5:1$. How many candidates had applied for the process?

In a college,$150$ students of $MBA$ are enrolled. The ratio of boys to girls is $7:8$. There are three disciplines in the college,namely,Marketing,$HR$,and Finance. In the Marketing discipline,there are $50\%$ girls of their total number and the boys are $40\%$ of their total number. In the $HR$ discipline,girls are $30\%$ of their total number while boys are $30\%$ of their total number. The Finance discipline has girls $20\%$ of their total number and the boys are $30\%$ of their total number. $7$ boys and $9$ girls are in the $HR$ and Marketing both. $6$ boys and $7$ girls are in the $HR$ and Finance both. $5$ boys and $8$ girls are in the Marketing and Finance both. $2$ boys and $3$ girls are enrolled in all the three disciplines. What percentage of students are enrolled in all three disciplines?

The ratio of the radii of two cylinders is $2:3$,and the ratio of their heights is $5:3$. The ratio of their volumes will be

Find the number which,when subtracted from the terms of the ratio $12: 17$,makes it equal to the ratio $2: 3$.

The present ages of $A$ and $B$ are in the ratio $5:6$ respectively. After seven years,this ratio becomes $6:7$. Then the present age of $A$ in years is: