Aptitude - Problems on Ages - Discussion

Thanks @Vaishu. You explained it very clearly. :).

Your clarification is very simple, Thanks @Vaishu.

I didn't understand the last step of the explanation. Please clarify me.

How is it 4x? I didn't get it please tell me clearly.

@Maqsood nice explanation. Thank you.

if Father is aged three times more than his son Ronit means, 3x + x = 4x then After 8 years, he would be two and a half times of Ronit's age.

In that above 'he' represent Ronit's father which means
(3x + 8) = 5/2(x + 8) right?

Then, how it will be (4x + 8) = 5/2(x + 8)?

It's so simple!

The value of x is ''8'' so 4 x is (4(8) + 16)/(8 + 16) and you get 48/24 = 2.

A is 2 years older than C and B is 2 years younger than C. The ratio of A's 6 years ago and B's 8 years ago is 6 : 5. Find C's present age.

Father F and Rohit R.
So, F = 3R + R = 4R.
After 8 years,
F + 8 = 2 1/2 (R + 8) means, F + 8 = 5/2 (R + 8).

So, 2(F + 8) = 5R + 40,
2(4R + 8) = 5R + 40,
8R + 16 = 5R + 40,
3R = 24,
R = 8.

Rohit's present age = 8 years.
After 16 years of present day (8 + 8).
Ratio would be F + 16/ R + 16.
So, 4R + 16/R + 16,
4(8) + 16/8 + 16 = 48/24 = 2.

You can also solve this problem by taking son's age as x and father's age as y. First, y = 4x as it is 3 times 'more' than that of his son. Then after 8 years son's age will be x+8 and father's age will be y+8=5/2(x+8) after solving you will get x = 8 and y = 32. Then after 16 years let father be n times of son's age i.e y + 16 = n(x + 16).

or 32 + 16 = n(8 + 16)
[putting x = 8 and y = 32]
or 48 = 24n,
or n = 2.

Therefore father is 2 times his son's age after 16 years.