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

The average age of women and child workers in a factory was $15 \text{ years}$. The average age of all the $16$ children was $8 \text{ years}$ and the average age of women workers was $22 \text{ years}$. If $10$ women workers were married,then the number of unmarried women workers is:

$A$ man is $24$ years older than his son. In $2$ years,his age will be twice the age of his son. The present age of the son is (in years):

$10$ years ago,Mohan was thrice as old as Ram was,but $10$ years hence,he will be only twice as old as Ram. Find Mohan's present age (in years).

The average age of $30$ students of a class is $14$ years $4$ months. After the admission of $5$ new students,the average age becomes $13$ years $9$ months. The youngest of the five new students is $9$ years $11$ months old. What is the average age of the remaining $4$ new students?

After replacing an old member by a new member,it was found that the average age of five members of a club is the same as it was $3$ years ago. The difference between the ages of the replaced and the new member is (in years):