The present age of father is three times as old as his son. 5 years ago, the father was four times as old as his son.

Correct option is (A) 30 years more than the son’s age

Let present age of father be x years and present age of son be y years.

5 years ago, the age of father = (x - 5) years

and the age of son = (y - 5) years,

After 5 years, the age of father will be (x+5) years

and the age of son will be (y+5) years.

According to given conditions, we have

x = 3y                            ___________(1)

And (x - 5) = 4 (y - 5)    ___________(2)

\(\Rightarrow\) x - 5 = 4y - 20

\(\Rightarrow\) 3y - 5 = 4y - 20          (From (1))

\(\Rightarrow\) 4y - 3y = 20 - 5

\(\Rightarrow\) y = 15

\(\therefore x=3\times15=45\)         (From (1))

Now, x+5 = 45+5 = 50

& y+5 = 15+5 = 20

\(\because\) x+5 = (y+5) + 30

Hence, after 5 years father’s age will be 30 years more than the son’s age.

Correct option is A) 30 years more than the son’s age