Aptitude - Percentage - Discussion
Discussion Forum : Percentage - General Questions (Q.No. 6)
6.
If 20% of a = b, then b% of 20 is the same as:
Answer: Option
Explanation:
20% of a = b  |
20 | a = b. |
| 100 |
 b% of 20 = |
 |
b | x 20 |  |
= | |
20 | a x | 1 | x 20 | |
= | 4 | a = 4% of a. |
| 100 | 100 | 100 | 100 |
Discussion:
73 comments Page 3 of 8.
SANKAR NAYAK said:
5 years ago
If 20% of a=b means B =(20/100)*a ----> eq(1)
And b%of 20 means (b/100)*20 ----> eq(2).
If we put eq(1) value in eq(2) Then,
[{(20/100)*a}/100]*100
If we simply fy it = {100/(100*20*a)}*20,
=> 1/(20*a)*20.
=> 1/a So ans is incorrect.
If we modify qn and put 20% of b then
(20/100)*b.
We put b value i.e b = (20/100)*a,
Then => (20/100)*(20/100)*a,
If we simply fy it , then,
(20*20/100*100)*a.
And answer will be (4/100)*a.
Means 4% of a.
And b%of 20 means (b/100)*20 ----> eq(2).
If we put eq(1) value in eq(2) Then,
[{(20/100)*a}/100]*100
If we simply fy it = {100/(100*20*a)}*20,
=> 1/(20*a)*20.
=> 1/a So ans is incorrect.
If we modify qn and put 20% of b then
(20/100)*b.
We put b value i.e b = (20/100)*a,
Then => (20/100)*(20/100)*a,
If we simply fy it , then,
(20*20/100*100)*a.
And answer will be (4/100)*a.
Means 4% of a.
(4)
Sriramamurthi said:
6 years ago
@All.
20% of a = b so in question they are given the b value.
Then b% of 20 do now,
Instead of b %, put the value of b,
20/100 of a*20 then cancel it properly. You will get the value of 4% of a.
That will be our required answer.
20% of a = b so in question they are given the b value.
Then b% of 20 do now,
Instead of b %, put the value of b,
20/100 of a*20 then cancel it properly. You will get the value of 4% of a.
That will be our required answer.
(2)
Prasad M said:
7 years ago
As percent always calculates at 100 ref. Let a= 100.
20% of a means - 20 which is b acc to question.
20 percent of again 20 (got above) is 4 percent of a.
This doesn't require any paper calculations I believe, Hope it helps.
20% of a means - 20 which is b acc to question.
20 percent of again 20 (got above) is 4 percent of a.
This doesn't require any paper calculations I believe, Hope it helps.
(3)
SABARI said:
7 years ago
20% a = b
when b is 20.
a = (20/100)*20,
a = 4.
when b is 20.
a = (20/100)*20,
a = 4.
(1)
Pavan said:
7 years ago
Anyone explain this.
(1)
Prajwal said:
7 years ago
(20/100)a=b ----> (1)
(b/100)*20=? --------> (2)
So substitute (1) in (2).
So we get [(20/100)/100]*20 ==>(4/100) ==>4% [because b=(20/100)a].
(b/100)*20=? --------> (2)
So substitute (1) in (2).
So we get [(20/100)/100]*20 ==>(4/100) ==>4% [because b=(20/100)a].
(1)
Qadir said:
7 years ago
20% of a = b --> Assume a as 100.
So, 20% of 100 = 20 By this we can say b=20.
Now, b% of 20 b=20% of 20=4 which is the answer.
So, 20% of 100 = 20 By this we can say b=20.
Now, b% of 20 b=20% of 20=4 which is the answer.
Sagar said:
8 years ago
Hi, I am not understanding this. Anyone explain me to get the answer.
Ubaid goje said:
8 years ago
Thanks @Swaminathan Vembu.
Narmadha said:
8 years ago
If you consider a=50, then the answer will not be 4%, there is no clue in the question that one should take a=100. When I assigned a=100 I got the answer as 4%, then when I assigned different value for a, the % varies.
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