The sum of the ages of a father and son is $45$ years. $5$ years ago,the product of their ages was four times the father's age at that time. The present age of the father is (in years):

$A$ man is $3 \, \text{years}$ older than his wife and four times as old as his son. If the son becomes $15 \, \text{years}$ old after $3 \, \text{years}$, what is the present age of the wife? (in $\text{years}$)

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:

Present ages of Sameer and Anand are in the ratio $5:4$. Three years hence,the ratio of their ages will become $11:9$. What is Anand's present age in years?

The ratio between the present ages of $P$ and $Q$ is $5: 7$. If the difference between $Q$'s present age and $P$'s age after $6$ $years$ is $2$,what is the sum of ages of $P$ and $Q$ at present? (in $years$)

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):