Aptitude - Problems on Ages - Discussion

Father F and Rohit R.
So, F = 3R + R = 4R.
After 8 years,
F + 8 = 2 1/2 (R + 8) means, F + 8 = 5/2 (R + 8).

So, 2(F + 8) = 5R + 40,
2(4R + 8) = 5R + 40,
8R + 16 = 5R + 40,
3R = 24,
R = 8.

Rohit's present age = 8 years.
After 16 years of present day (8 + 8).
Ratio would be F + 16/ R + 16.
So, 4R + 16/R + 16,
4(8) + 16/8 + 16 = 48/24 = 2.

You can also solve this problem by taking son's age as x and father's age as y. First, y = 4x as it is 3 times 'more' than that of his son. Then after 8 years son's age will be x+8 and father's age will be y+8=5/2(x+8) after solving you will get x = 8 and y = 32. Then after 16 years let father be n times of son's age i.e y + 16 = n(x + 16).

or 32 + 16 = n(8 + 16)
[putting x = 8 and y = 32]
or 48 = 24n,
or n = 2.

Therefore father is 2 times his son's age after 16 years.

How required ratio 4x + 16/x + 16 come?

@Yalleswari.

As per the statement, x + 3x.
After 8 years, he would be 2 and a half times of his son.

So, x + 3x + 8 = x + 8.
4x + 8 = x + 8.
(4x + 8 ) = 5/2(x + 8).

We get, 8x + 16 = 5x + 40 => 3x = 24.
x = 8.

After further 8 years,

So add 8 to the equation 4x + 8 + 8 = x + 8+ 8.
4x + 16 = x + 16.

So the ratio is, (4x + 16)/(x + 16) = 48/24.
=> 2 years.

Let the age of son be x then age of father will be 4x so we have ratio of father and son equals to 4x:x again after 8 years this becomes 5/2x:x as we all know that difference of age remains same then to make it same multiply above by 2 so that it becomes 5x:2x, therefore in 8 years 4x becomes 5x hence x is equal to 8 putting the value we get the age equal to 40 and 16 respectively and after 8 more years it will become 48 and 24 and hence father's age will be twice of son.

How you are getting 5/2?

Which has 1/2?

@Rekha.

2 and half times means 5/2 times.

Guys! It's three times more that mean 4x if it would be three times then we used 3x.

Hi friends,

It's three times more that, that is 3x not 4x.

Father is Tree times more than his son.

i.e. Ronit age is also considered while calculating his father age so, Ronit age+ 3*Ronit age = His father's age. Here " Father more than" this word is important.

If Suppose Question is as Father's age is three time the Ronit age then & then only it 3X.

2. Two & half means 2+1/2= 5/2.

Good luck!