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:
74 comments Page 8 of 8.

Akilapriya said:   1 decade ago
I can't understand the sentence "then the number of students in A is double the number of students in B" explain me.

Rcahana said:   1 decade ago
Please help me solve this.

PRAKASH said:   1 decade ago
I don't know how 2 was came at step 2.

Please explain.

Doss said:   1 decade ago
Dear friend explain with example.........


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