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
Answer: Option
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:
135 comments Page 7 of 14.

Rashid ali said:   9 years ago
The correct answer is 2:5.

I'm explaining bellow 20% means X is multiplied with 100.
For example : 95% of 80 = 80 * 95/100 = 76.
If you are agree with this concept then,

20% = 20/100 and 50/100.
20% = 1/5 and 50% = 1/2
A 1/5 : B 1/2 =2 : 5.

Hence answer is 2 : 5.

Abinash said:   9 years ago
If a and b incomes are in the ratio 9:4. Their expenditure are 8:3. Each saves rs 2500. Then expenditure of b?

Please tell me the answer for this.

Cik_nani said:   9 years ago
How do you get 120/100? And how do you get the answer 6 over 5? I'm confused. Please clarify me.

Shahjahan said:   9 years ago
How you get 120 and 150? Confused. Please help me.

Anjaney said:   9 years ago
@Kunal.

It is 100 because ratio should be treated as 100.

Rakesh said:   9 years ago
@Ganapathy concept is very nice.

Manishanaveen said:   9 years ago
The third number be x.
Let a and b are two numbers with more than 20% and 50% of x.

a = x + 20%x.
b = x + 50%x.

We should find ratio a : b.

a/b = (x + 20%x)/(x + 50%x) we know % converted into (/100),
a/b = (x + 20x/100)/(x + 50x/100),
so we get a/b = (100x + 20X/100x + 50x).

a/b = (120x/150x)
a/b = 4/5.

Ratio of a = 4 and b = 5.

Shortcut: So just us 100 as x for removing %
a =100 + 20.
b =100 + 50.

a : b = 120 : 150.
And hence a/b = 12/15.
a/b = 4 : 5
(2)

Dibya said:   9 years ago
Sathi concept is good.

Manish kumar said:   9 years ago
What to do, if asked for third number?

Sameer khan said:   9 years ago
Ganapathy and Ramesh concept are easy and right.


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