Aptitude - Problems on Ages - Discussion

First time more than 3 years of his son's age, after 8 years 2 and 1/2 years of Ronit age. Then finally 2 times of his son's age.

If you observe 1/2 times decreasing in ratio so its only guess.

Son age = x.

Father age = 3x+x.

4x+8 = 2.5 (x+8).
4x+8 = 5/2 (x+8).

2(4x+8) = 5(x+8).
8x+16 = 5x+40.

8x-5x = 40-16.
3x = 24.

x = 8.

Now follow the rest.

What is that? Father's age is 3 times of Ronit so is it came 4x?

If, X = 8 than, when son was 8 father was 24.

When son was 16 father will be 32.

How 32 is 2.5 multiplier of 16?

Please, explain last ratio.

Ten years ago Ram was thrice as old as Sham was but 10 years hence; he will be only twice as old. What is Ram's present age?

@Aishu.

Answer for your question:

http://www.meritanswers.com/questions/calculate-ram-present-age/17229-1-1

Why will we add 8 + 8?

Please explain.

Father is aged three times more than his son Ronit.

Then why father age = x, and Ronit age is = x?

Why not father age = x? And son Ronit age = y.

Let the present age of Rohit be 'x' years and the present age of the father be 'y' years. As per the question father is aged three times more than his son hence, y = x+3x = 4x.

Therefore present age of father is y = 4x.

Given that after 8 years, he would be two and half times of Rohit's age.

Therefore,

y+8 = 5/2(x+8).
4x+8 = 5/2(x+8) {since y = 4x}.
2(4x+8) = 5(x+8).
8x+16 = 5x+40.
8x-5x+16-40 = 0.
3x-24 = 0 => 3x = 24 => x = 24/3 = 8.
x=8,

After 8 years,

y+8 = x+8.
4x+8 = x+8 {since y = 4x}.

After further 8 years, 'k' times would be the Rohit's age.

Therefore,

4x+8+8 = k (x+8+8).
4x+16 = k (x+16).
k = (4x+16) / (x+16).
k = (4.8+16) / (8+16).
k = 48/24.
k = 2.

Therefore 2 times would he be Rohit's age.