Aptitude - Percentage - Discussion

Discussion Forum : Percentage - General Questions (Q.No. 8)
8.
Two numbers A and B are such that the sum of 5% of A and 4% of B is two-third of the sum of 6% of A and 8% of B. Find the ratio of A : B.
2 : 3
1 : 1
3 : 4
4 : 3
Answer: Option
Explanation:

5% of A + 4% of B = 2  (6% of A + 8% of B)
3

5  A + 4  B = 2 6  A + 8  B
100 100 3 100 100

1  A + 1  B = 1  A + 4  B
20 25 25 75

1 - 1  A =  4 - 1  B
20 25 75 25

1  A = 1  B
100 75

A = 100 = 4 .
B 75 3

Required ratio = 4 : 3

Video Explanation: YouTube Video

Discussion:
52 comments Page 2 of 6.

Breejesh said:   1 decade ago
@Nitiesh and @Allana.

I don't understand how 3a=4b that becomes a/b=4/3.

To me 3 is with a and 4 is with b so should not be it as 3:4.

Why answer is 4:3.

Vinod Anand said:   1 decade ago
According to Question is :

5xA/100 + 4xB/100 = 2/3(6xA/100 + 8xB/100).

5A+4B = 2/3(6A+8B).

15A + 12B = 12A + 16 B.

3A = 4 B.

A:B = 4:3 , Option (D).

PARUL said:   1 decade ago
3(5A+4B) = 2(6A+8B).
15A-12A = 16B-12B.
3A = 4B.
A:B = 4:3.

Lewisk said:   1 decade ago
Why is the answer 4:3?

3 is associated with a and 4 with b.

Therefore a/b = 3:4.

Can someone explain why it is vice-versa?

Rama krishna mahapatra said:   1 decade ago
Let us take x = 2 and y = 3.

If we find x/y,
Then we write x/y = 2/3.

Similarly here x/y = 4/3.
Here x = 4 and y = 3.

=>x:y = 4:3.

Vaibhav said:   1 decade ago
5a+4b = 2/3(6a+8b).

15a+12b = 12a+16b.

a/b = 4/3.

So ratio is 4:3.

Narendra umraiya said:   1 decade ago
5% of A + 4% of B = 2/3*(6% of A+8% of B).

Take % common.

3(5A+4B) = 2(6A+8B).

4B = 3A.

A/B = 4/3 = 4:3.

Mohit said:   1 decade ago
Why is the answer like this can you tell me?

Amrit said:   10 years ago
Mohit if 4B = 3A then we can consider 4*B = 3*A and now when you will simplify it as A/B will become A/B = 4/3 it means the ratio is A:B = 4:3.
(1)

Mazher said:   10 years ago
Can anyone tell me why we take 2/3 and multiply 3 in the left and the 2 in the right?

That's the first time seeing this property?


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