Aptitude - Problems on Ages - Discussion

The explanation given according to the question was absolutely right and i came to this conclusion after scratching my head for an hour. It has the logic. I represent the same model of question here under, both follows the same pattern.

Q: Five years hence the ages of Ram and his Son will be in the ratio 5:2. Three years ago, the ratio of their ages was 7:2. Find the present age of his son.

This would help you in clearing the doubts of this brain eating question.

Thanks.

@Fakrudin.

His son's age will be 15 year, please comment is am right or wrong. Thanks. If am wrong then please explain if I am right then I will be explain. Thanks.

Age n years ago means = x-n.
Let the ages of Kunal and Sagar 6 years ago be 6x and 5x years respectively.

Then, (6x+6)+4 = 11/(5x+6)+4 = 10.
Why you add the 6x+6, 5x+6.

6 year ago means x-n.

Current age = 6x-(6 year ago).
6x-(-6)+4 == 6x+6+4.

Hope you guys understood :).

They asked after four year, why we put the x=5. So we can add x=4. Answer me please.

Lets take Kunal and Sagar's age as x & y.

6 years ago, x-6/y-6 = 6/5 --> 5x-6y+6 = 0 -> A.

4 years hence, x+4/y+4 +11/10 --> 10x-11y-4 = 0 ->B.

Solve A & B,

y(Sagars age) = 16.

Let the 6 years ago ages was 6s & 5x;

Now at present; its ration is (6x+6)/(5x+5);

By next statement; 4 years hence; the age rations will become as; (6x+6+4)/(5x+6+4) = 11/10.

By its values x = 2;

Now as sagar's present age is = 5x+6 = 5*2+6 = 16 year;

Simple!

Let present ages of kunal and sagar be k and s respectively.

Then 6 years ago (k-6)/(s-6) = 5/6.

After 4 years (k+10/s+10) = 11/10.

After solving I got sagars age as 8 years. What wrong in this? Please help me.

As per concept you provided in ago we go for subtraction then how here addition of 6 done. Really I got confuse please help me.

Do it like this,

Let present age of Sagar & Kunal be "x" & "y".

Then, x-6/y-6 = 6/5....equation (1).

Similarly, x+4/y+4 = 11/10....equation (2).

From equation (1) on cross multiplication we get,

5x-30 = 6y-36.
5x = 6y-36+30.

5x = 6y-6.
x = 6y-6/5.

Substituting the value of "x" in equation....(2) we get.

10*(6y-6/5)+40 = 11y+44.

2*(6y-6)+40 = 11y+44.

12y-12+40 = 11y+44.

12y-11y = 44+12-40.

y = 16.