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:
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:
75 comments Page 7 of 8.
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.
Swathi hj said:
6 years ago
Why we take x-10 and y+10, can anyone tell me?
(1)
Hello said:
6 years ago
Where is Ramesh? The one who explained the previous question very simply in this same chapter.
(1)
Suresh said:
5 years ago
In step 1 how you got 100?
(1)
Pratham said:
5 years ago
Hello, can you please explain the last step i.e x=100 y=80?
(3)
Alpesh Patel said:
5 years ago
x-y=20
x=20+y ---> (1)
x-2y=-60 ---> (2)
20+y-2y=-60 --->(3)
+y-2y=-60-20
-y=-80
y=80
Sub value of y in eqn 1, we get;
x=20+80 = 100.
x=20+y ---> (1)
x-2y=-60 ---> (2)
20+y-2y=-60 --->(3)
+y-2y=-60-20
-y=-80
y=80
Sub value of y in eqn 1, we get;
x=20+80 = 100.
(11)
Sylvester said:
5 years ago
If 2A=B, Also A=2B.
A=80, B=40, in other words: A=40*2=80.
A=80, B=40, in other words: A=40*2=80.
(2)
Jayashri said:
5 years ago
I disagree, if A is double the number of B.
How can 100 be the answer?
As B is 60 if we double it we get 160.
How can 100 be the answer?
As B is 60 if we double it we get 160.
(5)
Ramesh pai said:
5 years ago
Let's c option C i.e. 100.
A exam hall ----------- B exam hall
100 ----------- 80
10 from A to B = 90 | 90.
1st condition satisfies:
Let's see the 2nd condition:
If 20 candidates are sent from B to A, then the number of students in A is double the number of students in B.
A exam hall ----------- B exam hall
100 ----------- 80.
20from B to A = 120(100+20) | 60(80-20).
Therefore 100 is the right answer.
A exam hall ----------- B exam hall
100 ----------- 80
10 from A to B = 90 | 90.
1st condition satisfies:
Let's see the 2nd condition:
If 20 candidates are sent from B to A, then the number of students in A is double the number of students in B.
A exam hall ----------- B exam hall
100 ----------- 80.
20from B to A = 120(100+20) | 60(80-20).
Therefore 100 is the right answer.
(5)
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers