Aptitude - Problems on Ages - Discussion

Hello guys my problem is this why 5/2 is multiplied with (x+8) not with (4x+8). When question is saying father's age would be two and half time of ronit age.

Let us assume father age is x.

G. T father age is 3 times greater than rohit age so (x+3x) = 4x.

G. T after 8 years he would be two and half times of ronit's age so 2 (1\2) = 5\2 (2*2+1) /2.

After further 8 years.

(4x+8) = 5/2 (x+8).
8x+16 = 5x+40.
8x-5x = 40-16.
3x = 24.
x = 8.

After further 8 years.
(4x+8) = (x+8).

Add 8 then.

(4x+8+8) = (x+8+8).
(4x+16) = (x+i6).

Required ratio = (4x+16)/(x+16) = 48/24 = 2 (sub x=8).

Fathers is aged three times more than his son Ronit.

Assume Ronit's age is x.

Hence fathers age is 3 times more (3x) + in Ronits (x)age,

Which gives, (3x+x) that is 4x.

Actually the point is Ronit's father is more than 3 times. So 4x is absolutely right.

Father can't comes to sons age i.e. Father can't come to Ronit's age. Have doubt in?

Three times parents age of a father is equal to eight time age of his son. Eight years hence the father will twice as old as his son at that time. What are the parent ages?

Can any body solve this question?

Let,

Father = X.
Ronit = Y.

1st case:
X = 3Y.

2nd case:
X+8 = Y/2.

Third case:
X+16 = Y.

2X+16 = 3Y. From 1st and second case.

Then subtract third case in it. You will get,

X=2Y.

@Newbie.

You made a wrong calculation 3*16 = 48 and 52+16 = 68.

For all your folks let me tell my method.

First he has given father's age is 3 times of rohit so if rohit age 1, then his fathers will be 1+3=4 i.e. the ratio will be 4:1.

Now after 8 years the ratio given is (2.5) :1.

Now 4-1=3.

2. 5-1=1. 5 for my method you have to keep the difference in two ratios must be same, so multiply (2.5) :1 with 2. It becomes 5:2 i.e. 5-2 = 3 the difference is same as of 4-1=3 now remember we got 5:2 after 8 years i.e 4:1.

8 years hence 5:2

Now 5-4=1= 8 years.

So that makes 40:16.

After further 8 years 48:24 i.e.TWISE (2 times).

Let Ronit's age = x.

Father's age = x+3x (three times more than his son Ronit) = 4x.

After 8yrs.

Ronit's age = x+8.

Father's age = 4x+8.

But father will be two and a half times of Ronit's age so.

4x+8 = 5/2 (x+8).

x = 8.

Further after 8 years.

Ronit's age = x+8+8 = x+16.

Father's age = 4x+8+8 = 4x+16.

We know the value of x is 8 so putting value of x.

Now,

Ronit's age = x+16=8+16=24.

Father's age = 4x+16 = 4*8 +16 = 32+16 = 48.

Now we will calaulate the ratio of father's to ronit's age.

Father's age/ronit's age = 48/24 = 2.

Thus 2 is answer.