The mean proportional between $64$ and $81$ is

The present ages of three persons are in the ratio $4: 7: 9$. Eight years ago,the sum of their ages was $56$. Find their present ages (in $years$).

One year ago,the ratio of Ramu's and Somu's ages was $6:7$ respectively. Four years hence,their ratio will become $7:8$. How old (in years) is Somu?

$A$ sum of money is to be distributed among $A, B, C$ and $D$ in the proportion of $5: 2: 4: 3$. If $C$ gets ₹ $1000$ more than $D$,what is $B$'s share (in ₹)?

At present,Anil is $1.5$ times Purvi's age. $8$ years hence,the respective ratio between Anil and Purvi's ages will be $25:18$. What is Purvi's present age (in years)?

The ratio between two numbers is $2: 3$. If each number is increased by $4$,the ratio becomes $5: 7$. The numbers are: