Question

There are two examination rooms A and B. If 10 candidates are sent from A to B, the number of students in each room is same. If 20 candidates are sent from B to A, the number of students in A is double the number of students in B. Find the number of students in each room.

Answer 1

Let the number of students in room A be x and that in room B be y.

As per the question, x - 10 = y + 10
⟹x−y=20−−−−−(1)
Also, x + 20 = 2(y - 20)
⟹x−2y=−60−−−−−(2)
On solving eq (1) and (2) we get,
x = 100 and y = 80