Aptitude - Problems on Ages - Discussion

When it is "three times more" why should we take (3x+x)? It can also be (3x+2x) or (3x+.5x)?

Hi @Annapoorna,

It is supposed of x years for son and in question father is more than 3 years of son so that it is of (3x+x). Thanks.

What is the meaning of last line of Question?

And how it is resolved?

How do we get (4x + 16) divide by (x + 16) instead of (4x+16)=(x+16)?

There are times when we take x & y both variable. So how to identify whether we have to use 1 variable or both?

For this sum answer should be option(B) which is 5/2 in fraction and in mixed fraction which is 2 1/2.

Two and half times means : 2.5.

Multiply both numerator and denominator by 2.

Thus,

2.5 x 2 / 1 x 2.

5/2 or 2.5.

It doesn't make sense why ppl take the fathers age as 4X just becos its says 'times more' . what if the son's age is 'times less' of the father? :D

So I made a calculation based on logic and it comes to this
son's age = x.
Father's age = X x 3 = 3X.

After 8 years father is 2 and half years older than his son, so if we add 8 years to the fathers age it will be equal to 2 and a half times of the son's age.

i.e 3X + 8 = 2 and a half times of X.
3X + 8 = 2 1/2 x X.

From the equation X = 16.

Now the fathers initial age = 3X.
= 3 x 16 (X=16).
= 52.

After 16 years (8+8 years) father will be,
= 52 + 16.
= 64.

In the same way the son after 16 years will be,
= X + 16.
= 16 + 16 = 32.

Hence the difference of their age will be, 64 divided by 32
= 64 / 32.
= 2.

So the Father will be 2 times older than the son in 16 years :D.

And as @newbie said, if its correct then I am failing to understand that why is 3x + 8 = 2.5 x ? Shouldn't it be 3x + 8 = 2.5 (x + 8), because even the son's age should have been added to 8 right ?

Fathers age is 3 times more than his son 4x.

But after getting full stop considering and comparing other sums I can understand like this (x+8). How we put (4x+8) in fathers age?