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 5 of 8.
Rajesh said:
9 years ago
We can find out the answer by option if the 1st option is 80. Consider the student of class B and transfer 10 students then in both the class are equal so definitely, A class has a 100 student then tally it.
Ramesh.Mariyada said:
9 years ago
Exactly I have the same doubt as same as @Nandhakumar.
Can anyone help us?
Can anyone help us?
Cgyel said:
9 years ago
If A is double then, Why 2 (y - 20)?
Kavya said:
9 years ago
It is A which is double. So the equation should be 2 (x + 20) = y - 20. Right?
Naveena said:
9 years ago
Friends you are doing upto x and why values. But we have to double the A also comparing to B.
Chandrasekhar said:
9 years ago
Students sent from A to B = 10;
Then A-10 = B+10; ---- (i)
Students sent from b to a = 20; then,
B-20 = A+20; --- (ii).
A is double no.of students in B so,
2(B-20) = A+20.
Solve 1 & 2, we get,
A = 100.
Then A-10 = B+10; ---- (i)
Students sent from b to a = 20; then,
B-20 = A+20; --- (ii).
A is double no.of students in B so,
2(B-20) = A+20.
Solve 1 & 2, we get,
A = 100.
(1)
Idhaa said:
10 years ago
2 has come because there are two rooms in the question.
Manish Kumar said:
1 decade ago
I couldn't get how we solve both equation please make it clear by multiply.
Prashant said:
1 decade ago
Assume maximum capacity of both side 100 and subtract 20 from it a:b = 100:80.
Prashant said:
1 decade ago
It is very simple assume maximum capacity of seats in both room is 100, now A:B = 100:80.
There is no need to think about 1st equation or second just do maximum-lesser no. of side.
There is no need to think about 1st equation or second just do maximum-lesser no. of side.
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