Question

the age of a father is twice the sum of its two children after twenty years his age will be equal to the sum of age if its children find age if father

Answer 1

Let the age of father be x years and sum of age of his son be y year.
A/q
$x = 2y......(1)$
Again,after 20year.
$2y + 20 = y + 40\\ Y=40-20\\ y = 20 \\ - x = 40$
Hence,the age of his father is 40years.