# Aptitude - Ratio and Proportion - Discussion

Discussion Forum : Ratio and Proportion - General Questions (Q.No. 2)
2.
Two numbers are respectively 20% and 50% more than a third number. The ratio of the two numbers is:
2 : 5
3 : 5
4 : 5
6 : 7
Explanation:

Let the third number be x.

 Then, first number = 120% of x = 120x = 6x 100 5

 Second number = 150% of x = 150x = 3x 100 2

 Ratio of first two numbers = 6x : 3x = 12x : 15x = 4 : 5. 5 2

Discussion:
122 comments Page 1 of 13.

Let third no be 100.
the first no is 20% more than third so 120
similarly
second no is 50% more than third so 150
just compare
120:150
4:5
(2)

Suppose the 3rd no is X.
so 1st no will be X*1.2.
&2nd no will be X*1.5.
so the ratio is 1.2:1.5,
Hence 4:5
(1)

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

20%=1/5
50%=1/2

So ratio should be equal to 1/5:1/2

Ans= 2:5 ?
(1)

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.

Let 3rd no is x
20%of x=(20/100)*x
50%of x=(50/100)*x
1/5x:1/2x
ans=2:5

I do know understand this concepts please explain.

Let it be of 100. It is most convennience.

Take A,B,C as three numbers

A is 20% more than C

A=C+20%of C=C+0.2C=1.2C

same way

B=C+50%of(C)=C+0.5C=1.5C

ratio A/B=1.2C/1.5C=4/5

Ans 4/5