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:
116 comments Page 1 of 12.

ALI said:   1 decade ago
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....

Manishanaveen said:   7 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

Shakti said:   2 years ago
Let 3rd number is "c" and the 1st and 2nd is;
A,B.

Then,
A is the 20% more than c.
Means A = c+20%c.
= c+.2c.
= 1.2c.

Same hear,
B is the 50% more than of c.
Means. B = c + 50%c.
= c + .5c,
= 1.5c.
Then the 2 number ratio is,
A:B = 1.2c:1.5c.
(Multiply in both sides 10 to avoid the decimal point)
1.2c * 10:1.5c * 10.
12c:15c,
4:5.
(2)

Anish Sharma said:   8 years ago
Listen 20% more than third no and 50% more than through number.

So, First-> solve the 20% = 20/100 = 0.2.

But 20% more than third no, so we will add a third no.

And assume the third no. is x and x mean (1x) not a simple x.

So 0.2+1x = 1.2.

Second-> same for 50% = 50/100 = 0.5.

0.5+1x = 1.5.
= 1.2:1.5.
= 12:15.

So you can say: 4:5.

Akshay said:   8 years ago
@Nive.

Method is actually according to the question approach. Its is valid.

a = c+20%.

b = c+50%.

a/b = 100c+20/100c+50.

Now c definitely having some value so consider it as 1 we can't consider it as 0 because it has some value and on other hand we have to consider it as 1 because it has some non zero value.

So a/b = 0.8 i.e. 4/5.

Ramanan said:   7 years ago
Let the third number be x given that:

x+20% : x+50%.

x+0.2 : x+0.5.

(we know x is '1x').

So, 1x+0.2 : 1x+0.5.

= 1.2x : 1.5x.

(To remove decimal points we are multiply in both sides by 10).

= 1.2x*10 : 1.5x*10.

= 12x : 15x.

By simplifying,

= 4 : 5.

(x will get cancelled when 12x/15x).

Valar morghulis said:   6 years ago
I have a doubt that most people are facing here it seems:

It's written 20% more than the third number so we took Z(third number) + (20/100)*Z.
What should be written if the equation comes as Z + 20/100?
Please, someone, take a time to help me and clarify this.
Thank you.

Rashid ali said:   6 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.

Niz said:   8 years ago
If a, b, c.

a = c + 20% of c.

i.e a = c + 20/100*c.

a = c + 0.2 c.

i.e 1.2 c.

Also b = c + 50% of c.

i.e b = c + 50/100*c b = c + 0.5 c.

i.e 1.5 c.

Ratio between three numbers.

= 1.2 c : 1.5 c : c.

= 1.2 : 1.5.

i.e 4 : 5.

Ravi said:   6 years ago
Simply, we all know that in Case Of percent 100 % is max percentage.

So take 3rd number be 100%
A say more than 3rd no. That is 20%+100%=120% or 1.2
B say more than 3rd no. That is 50%+100%=150% or 1.5
Now, divide A/B=1.2/1.5=4:5.


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