Verbal Reasoning - Arithmetic Reasoning - Discussion

Discussion Forum : Arithmetic Reasoning - Section 2 (Q.No. 6)
6.
A father tells his son, "I was of your present age when you were born". If the father is 36 now, how old was the boy five years back ?
13
15
17
20
Answer: Option
Explanation:

Let the father's age be x and the son's age be y.

Then, x - y = y or x = 2y,

Now, x = 36. So, 2y = 36 or y = 18.

Therefore Son's present age = 18 years.

So, son's age 5 years ago = 13 years.

Discussion:
6 comments Page 1 of 1.

Shah Rukh Khan said:   9 years ago
Let son's present age be 'x' which was his father's age when he was born. so..
---------------------
father son
x 0
36 x
---------------------
As father and son's age difference will same forever. So..
x - 0 = 36 - x
=> 2x = 36,
=> x = 18,
Son's present age = 18.
5 years back son's age was = 18 - 5 = 13.
(2)

BHOOTHNATH said:   1 decade ago
Father son.

x year 0 year.
36 year x year.

So son grow from 0 year to x year = father grow form x year to 36 year.

If we deduct sons current age x year form current 36 year of father current age we get fathers x year age (which is equal to sons current).

So 36-x = x or 18 = x or 13 = sons age before 5 year.

VINOJ said:   1 decade ago
@Muhammed.

x is father's age and y is son's age means. x-y=y means, suppose if father is 36 and son is 25, then will that satisfy that equation? or you are saying "Before the son was born fathers age was (fathers age - sons age)" son is 0. Then why this equation? You can directly say fathers age!

Muhammed Shad said:   1 decade ago
Bro, the age of son is y years. Before the son was born fathers age was (fathers age - sons age) which is according to the question is equal to the present age of son that is y years.

So x-y=y :).

Hope your doubt is cleared. :).

Prathipan Kasinathan said:   1 decade ago
How it can be possible x-y = y or x = 2y.

Is there in question doesn't mention like father age double time of son age.

Nagaraju parasa said:   1 decade ago
Father present age 36 off of the sun age is 18 so 5years ago sun age is 13years.

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