Aptitude - Problems on Ages - Discussion

I think answer is 2.2 times.

x = son Ronit's age now.

3x = father's age now <--- father is 3 times son.

x + 8 = Ronit's age in 8 years.

3x + 8 = father's age in 8 years.

3x + 8 = 2.5 (x + 8) <--- after 8 years, father is 2.5 times son.

3x + 8 = 2.5x + 20 <--- used distributive property.

0.5x = 12 <--- subtracted 2.5x and 8 from each side.

x = 24 <--- divided each side by 0.5.

3x = 72 <--- substituted 24, in for x, into 3x.

Son Ronit is 24 now & father is 72 now.

Son Ronit will be 32 in 8 years & father will be 80 in 8 years.

Son Ronit will be 40 after further 8 years & father will be 88 after further 8 years.

Father will be 2.2 times son after further 8 years.

The last step is easy but division sign gone somewhere else. Fathers age is 4X + 8 + 8 (here 8 + 8 are the years later) now divide this with sons age which is x. But after 8 + 8 years it would be x + 8 + 8 as we got x value substitute in the both numerator and denominator there you go you get as 48/24 and we taking in ratio forms as options are given in ratio like two times the son age etc.

How it is 4x?

Father's age is three times more than his son's age means. We can say (3x+x) or (3x+2x)...

Why we take it as (x+3x)?

In last step why the equations are divided? Why ratio is taken?

Aafreen Rah:

Its 3x+x because "Father's age is 3 times (3x) more than (+) his son's age (x)". Here son's age is "x" so just add "x" age to 3times (3x).

Hello @Sundar,

Please tell me how did you take [(4x + 16)/(x + 16))]this ratio.

(4x + 16)/(x + 16).

All are wrong answer.

Current answer is 2 1/5 time.

That is father first age is 72 answer his son age is 24 (3:1).

After 8 years father age is 80 and son age is 32 (1: 2. 5).

After 8 years father age is 88 and son age will be 40 (1: 1. 2).

So all option are incorrect.

Suppose age of Rohit is x so, age of father is 3x.

Now, (3x+8)/(x+8) = 2.5/1.

We get x = 24.

So age of father = 3*24 = 72.

So that after 8 the ratio became 2.5:1.

Further after 8 years. The ratio is 88/40 = 2.2.

But I don't get the answer 2.

I have no doubt after all yours discussion to simple answer, thanks all of you.

How is come x+16?