Aptitude - Problems on Ages - Discussion

How you got the value as x=20 while solving this 2 equ x=30 is coming how if possible please solve that 2 equ please.

@Bharat

It is simple. Here we are considering for after 10 years but the question is to find ratio of the present age.

So, (3x+10):(x+10) as x=20

Subs in the above equation, You will get 7:3.

We can do this problem by this method:
let the age of the son be x
let the age of the father be y
10 years ago
x-10=y-10
father was 3times the son so,
3(x-10)=y-10
3x-30=y-10
3x-y=20........1 equation
10 years hence
x+10=y+10
father was 2times that of the son
2(x+10)=y+10
2x+20=y+10
2x-y=-10........2equation
now solve the equation 1 and 2.

Can any one tell me how to derive the ratio?

Thanks nagu.

Hi all,

There is no like we should subtract
We need to finish with simple way so

They are taking 10 years ago they boy age is x
Then the father's age is 3x

So now the age of boy and father is x+10 and 3x+10

So 10 years hence it will be x+10+10 and 3x+10+10

But as per problem fathers age is double than his son

So (3x + 10) + 10 = 2[(x + 10) + 10]

Hope this will help you. Have a nice day.!

For 10 years ago it should be minus 10 give me reason please ?