After five years the age of a father will be thrice the age of his son whereas five years ago, he was seven times as old as his son was. What is father's present age ?

After five years the age of a father will be thrice the age of his

1.	After five years the age of a father will be thrice the age of his son whereas five years ago, he was seven times as old as his son was. What is father's present age ?
A.	40 years
B.	30 years
C.	20 years
D.	10 years
Answer» B. 30 years