Aptitude - Problems on Ages - Discussion

Answer is 2.

ratio
F:S
3:1 After 8 yr.
5:2

(check differance |3-5|=2 & |1-2|=1 we know that ratio diff. must be same bcoz father age +8 with son age also +8 yr).

F:S
9:3 - - - >(x3)
10:4 - - - > (x2)
diff. =1 because of +8yr.
i.e 1=8.

The resent age father 3x8=24 + after 8 yr = 32.
The present age son 1x8=8 + after 8 yr = 16.

F/S=32/16= 2.

How 5/2 came? Can anyone explain.

(4x+8) = 5/2(X+8).
= 8x+16 = 5x+40 how it came?

@Amrutha.


The correct answer is 11:5.

Fathers present age :72
Son's present age :24
So ratio:- 3:1

After 8 years:
father's age: 80
son's age: 32
so ratio:- 5:2

Further 8 years after:
Father's age : 88
Son's age: 40
So ratio : 11:5 is the correct answer.

Son- x father- 3x BUT, it is said MORE than 3 times so x +3x= 4x.

Now, 8 years ahead, son= x+8 and father= 5/2*(x+8).
---> (x+8)=5/2*(x+8),
---> 2(x+8)=5(x+8),
---> 2x + 16= 5x + 40,
---> x= 8 - sons age.
father is 4x= 4*8= 32.

NOW, in total 16 years is asked from the beginning,
So, sons age= 8+16= 24,
Fathers age= 32+16= 48,
48 is 2 times of 24!.

I think 2.5(x+16) = (4x+16).

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 the son.

As it is said that father's age is 3 times more than his son's.

So father's present age 3x and son's age x.
After 8 yrs their age will be,
3x+8 = 5/2(x + 8),
3x+8 = ((5x)/2) + (40/2),
2 * (3x+8) = 5x + 40,
6x + 16 = 5x + 40,
x = 24.

So son's age will be 24.
And father's age will be 3x = 72.

Further 8 more years ie; after 16 years,
Son's age will be x+16 ie; = 40,
and father's age will be 3x+16 ie; =88,

Therefore (x+16) ÷ (3+16) = 2.2.

Father age can be taken as x.
Son age is taken as y.

According to the first statement, father age is three times more than sons age at present is x=3y

According to the second statement after 8 years father age is 8 times more than the two and a half age of son age.

2*1/2 can be written as 5/2.
So, x+8=5/2y.
Substitute x=3y,
3y+8=5/2y,
3y-5/2y=-8,
1/2y=-8.
y=-16 after 8 years.
After 8 years father age is twice than son age.
Then after 16 years also twice than son ager.

Ronit age = X.
Father age = 3x.
After 8 years.

(X+8) = (3x+8).
Half of of Ronit age.
(X+8) =1/2(3x+8).
X=8.

After further 8 years.
Both age ratio, where X = 8.
(3x+8)/X+8 = 32/16.
=> 2.