Question

A father is 20 years older than his son. After 3 years, the ratio of their ages will be 19/39. How old is the son today

Answer 1

age of son=X
age of father=20 +X
ratio at present =X:X+20

after 3 yrs
son=X+3 yrs
father=20+X+3 = 23+X yrs
ratio X+3 : 23+x =19:39
=>(X+3)39=(23+X)
39x +117=19x+437
39x-19x=437-117
20x =320
X=16
sons age is 16 years

Answer 2

Let the age of his son = 'x'

Given that the age of his father is 20 years older than his son.

Age of father = x + 20.

After 3 years;

⇒ Age of his son = x + 3.

⇒ Age of father = x + 23..

Now,

After 3 years, the ratio of their ages will be 19/39.

⇒ (x + 3)/(x + 23) = 19/39

⇒ 39(x + 3) = 19(x + 23)

⇒ 39x + 117 = 19x + 437

⇒ 20x = 320

⇒ x = 16.

Therefore, the age of son is 16 years.

Hope it helps!