Aptitude - Simplification - Discussion

Discussion Forum : Simplification - General Questions (Q.No. 2)
2.
There are two examinations rooms A and B. If 10 students are sent from A to B, then the number of students in each room is the same. If 20 candidates are sent from B to A, then the number of students in A is double the number of students in B. The number of students in room A is:
20
80
100
200
Answer: Option
Explanation:

Let the number of students in rooms A and B be x and y respectively.

Then, x - 10 = y + 10      x - y = 20 .... (i)

     and x + 20 = 2(y - 20)      x - 2y = -60 .... (ii)

Solving (i) and (ii) we get: x = 100 , y = 80.

The required answer A = 100.

Discussion:
76 comments Page 2 of 8.

Pratham said:   6 years ago
Hello, can you please explain the last step i.e x=100 y=80?
(3)

Suresh said:   6 years ago
In step 1 how you got 100?
(1)

Hello said:   6 years ago
Where is Ramesh? The one who explained the previous question very simply in this same chapter.
(1)

Swathi hj said:   6 years ago
Why we take x-10 and y+10, can anyone tell me?
(1)

Prakash said:   6 years ago
Could you please explain this? I am not getting it.

Prakash said:   6 years ago
Could you please explain this? I am not getting it.

Sagar said:   6 years ago
Thanks @Naga invy.

Geetha said:   6 years ago
Please Explain the 2nd step.

Chandu said:   6 years ago
We have to only subtract 10 students from A ie;A-10=B (OR) A=B+10.

But how do you add 10 to A sub 10 from B at a time that means 20 students are sending to B from A.

A-10=B,
B-20=2B=>B=20,
A-10=20,
A=30.
(1)

Sarvesh said:   6 years ago
Thank you @Naga.
(1)


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