Question

a man is four times as old as his son. after 20 years, he will be twice as old as his son at that time. find their present ages

Answer 1

Let the present age of son be x
Then father's present age will be 4x
After 20 years
age is son=x+20
age of father=4x+20
A.T.Q
4x+20=2 (x+20)
4x+20=2x+40
2x=20
x=10
Present age of son is 10
and present age of father is 40

Answer 2

Answer:

Lets Use ALTERNATIVE Method

Step-by-step explanation:

Let the present age of son be x

Then father's present age will be 4x

After 20 years

age is son=x+20

age of father=4x+20

So

4x+20=2 (x+20)

4x+20=2x+40

2x=20

x=10

Present age of son is 10

and present age of father is 40