Aptitude - Ratio and Proportion - Discussion

Hey guys plz don't bother!
let us make it simple...
it was said that first number is 20% more than third number
and second number is 50% more than third number..
now,
we assume the third number is "x".
we all know that "x" means "1x" not just "x"

so 20% more and 50% more than third number means
(20%)+(1x) and (50%)+(1x)
=(0.2)+(1x) and (0.5)+(1x)
=1.2x and 1.5x
now
1.2 : 1.5
let us forget the decimal and assume it 12 : 15
now simplify 12 : 15
i.e divide it by 3.
you'll get 4:5

that's it....

Let, The 3rd number be 100.

Then the 1st number is more than 20% than the 3rd number so 100+20=120.
Similarly, 2nd number is 100+50= 150.
Now the ratio of two numbers,
120:150,
4:5.

@All who have a doubt that why does 100 only comes in place of x.

It is so because percentage is always 100. Therefore x = 100.

Let the third number be 100.
Then 20% of 100 is 20,
And 50% of 100 is 50,
Then the 1st number is 120,
The 2nd number is 150,
So, the ratio between 120 and 150 is 4:5.

Thanks.

Here, Why should we consider 100? Please explain.

Yes, option C 4:5 is the right answer.

@Suhel Patel.

How did you take the third number as 100? Anyone, explain to me.

120/100 : 150/100
120:150
12:15
4:5

Dear xyz, it is not 20% and 50%, but it is 20% and 50% MORE THAN third number.

If third no is 100, it is 120 and 150
So, 120 : 150
12: 15 or
4:5

Why should take the value of third no is 100 only? why not 60, 70, 80.