Question

The age of Father is twice the sum of the ages of his two children after 20 years he is equal to sum of age of his children find the age of father

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.

Answer 2

Hey

Here is your answer,

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

According to the question

X = 2y
Y=2/x

Then after 20 years the age of father will be (x + 20) years and the sum of ages of two children will by (y + 2 × 20) = (y + 40) years

also x + 20 = y + 40 ... (2)

putting the value of y from (1) in (2) we get

X+20 = x/2 + 40
X+20 = x+80/2
2x+40=x+80
2x-x=80-40
X=40


Hence the age of the father is 40 years.

Hope it helps you!