Aptitude - Problems on Ages - Discussion

Father (F) = 3S (son).

After 8 year;
F + 8 = 5/2(S + 8)
Put F = 3S.

After Solution S = 24.
Now in the present time so before 8 year;
S =24 - 8 = 16.
Now F = 3S.
F = 3×16 = 48.
After further 8 years.
So, Father/son = 48/24.
Ans. 2.

As per the question, Father's age is 3 times more than the sons age.
Not 3 times of son's age..
That's why here is 3x+x.
Sons present age is = x
Father present age is = x+3x= 4x
After 8 years father's age would be -
4x+8 = 5/2(x+8).

By solving we get x=8,
now son's present age is x=8.
Father's age is 4x = 4*8= 32.

The required ratio 32+16/8+16 = 48/24 = 2 ans.

Say Sons age is X;

F = 3X
3X + 8 = 5/2(X+8).
6X + 16 = 5X+40.
X = 40 - 16,
X = 24.

So, 3X+16/X+16.
= 3 * 24+16/24+16.
= 88/40.
= 2.2.
Means -> 2 1/5.

A) 2 and a half times old= 2 1/2 = (2*2+1)/2 = 5/2.

B) Initially father is 3 times son's age.
After 8 years father is 2 1/2 times the son's age.
Again after 8 years father is? Times sons age?

Therefore, 0+8+8= 16.

Hence the equation 4x + 16/ x+ 16.

Can someone please tell me how?

=> (4x+8) =5x+40 Became
=> 8x+16?

I really didn't understand this part. Anyone help me to get it.

At present, F and R.

R=R,

Father's age would 3 times more than Ronit's age
F=3R+R -> F=4R -----> (1)

After 8 years, F+8 and R+8.

Father would be 2 and half a times of Ronit's age
F+8=2 1/2(R+8).

Mixed fraction 2 1/2 = ((2*2)+1)/2 = 5/2.
F + 8=5/2(R+8),
2F+16 = 5R + 40,
2F-5R = 40 - 16,
2F-5R = 24 -------> (2)

Sub F=4R in (2).
2(4R)-5R = 24,
8R-5R = 24,
3R= 24.
R = 8 years, F = 32 years.
After further 8 years means;
F + 16 = 32 + 16= 48,
R + 16 = 8 + 16= 24,
Required ratio= 48/24 = 2.
Hence, After further 8 years, 2 times he would be of Ronit's age.

If we will take Rohit's age I think it should be 3x (x+3).
If we will take Rohit's age as 1 it can be 4 only.

Correct me, If I am wrong.

@All.

Please explain, father is two and a half mean 5/2. Then why we write 5/2 With son's age?

Because when any question ask father is 5 times of son then we put father is 5x and son is x.

Anyone, please explain this.

Anyone, Can you explain this sum by taking 2.5?

If we take 2.5 or 5/2 will we get the same answer? Anyone explain.