Aptitude - Problems on Ages - Discussion

Hi to all, the solution to this question goes like this;

Let the present age of Kunal & Sagar be "X" & "Y".

For Six years ago, X-6/Y-6 = 6/5....situation (1).

For Four years hence, X+4/Y+4 = 11/10....situation (2).

From situation (1) we will calculate value of "X".

5X-30 = 6Y-36 (On cross multiplication).
5X = 6Y-36+30.
5X = 6Y-6 => x = 6Y-6/5....equation (i).

Now from situation (2), we substitute the value value of "X" in situation (2):

10x6Y-6/5 + 40 = 11Y+44.

Dividing denominator "10" by "5" in numerator we get.

2x6Y-6 + 40 = 11Y+44.
12Y-12+40 = 11Y+44.
12Y-11Y = 44+12-40.

Y = 56-40.
Y = 16.

In 6 years ago means -6 is comes why you have to use +6 in this equation?

@Faruk explained clearly, see it @Bhuvana.

Here we are calculating the present of Sagar, so instead of subtraction they used addition.

Six years ago : x-6/y-6 = 5/6.

5x-30 = 6y-36.

5x-6y = -6-----equation 1.

Four years after: x+4/y+4 = 11/10.

10x-11y = 11y+44.

10x-11y = 4------equation 2.

By solving equations 1 and 2 we get y = 16.

Why we add 6 years instead of subtracting in some cases if we got 6 we are subtracting why in this we are adding 6?

I can't understand this problem. Why they are adding 6 instead of subtracting?

Yes same here. They have clearly given in the important formula section that when statement contains the word "ago", have to subtract the number of years.

Why 6 is added? It should be subtracted.

How did you write the expression (6x+4) from the ratio explain it?

Always we need to substract if it is given ago.

So mounika's answer is absolutely correct. The solution they gave is wrong.