Question

the age of father is twice the sum of the ages of his two children after 20 years his age will be equal to the sum of his children what is father's age​

Answer 1

Let the sum of the ages of two children will be x and age of father will be y.

A.T.Q. , 

y = 2x                                              ----------(i)

and , After 20 years,

x+40=y+20 

==> x-y= -20

put y = 2x from (i),

x-2x = -20

==> x = 20

Now, put x= 20 in (i),

y = 2 x 20 = 40

Hence age of father will be 40 years.