Eighteen $years$ ago,the ratio of $A$'s age to $B$'s age was $8: 13$. Their present ages are in the ratio $5: 7$. What is the present age of $A$ (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 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):

The age of a father is twice that of his elder son. Ten years hence,the age of the father will be $3$ times that of the younger son. If the difference of ages of two sons is $15 \text{ years}$,the age of the father is (in $\text{years}$)

The ratio of the present ages of Swati and Trupti is $4:5.$ $6 \text{ years}$ hence the ratio of their ages will be $6:7.$ What is the difference between their ages? (in $\text{years}$)

In a family,mother's age is twice that of daughter's age. Father is $10 \,years$ older than mother. Brother is $20 \,years$ younger than his mother and $5 \,years$ older than his sister. What is the age of the father? (in $years$)