Problems on Ages - General Questions

A father is 5 times as old as his son. After 7 years he will be 3 times as old as his son. What is the father's present age?

The ratio of the present ages of A and B is 7 : 5. After 5 years the ratio will be 27 : 20. What is A's present age?

The sum of the ages of two brothers is 26 years and the elder is 8 years older than the younger. What is the age of the elder brother?

4 years ago, A was 4 times as old as B. A is now 9 years older than B. What is B's present age?

A father is 3 times as old as his son. After 8 years he will be 2 times as old as his son. What is the father's present age?