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.

Let the number of candidates in rooms A and B be ‘a’ and ‘b’ respectively.


Given, if 10 candidates are sent from A to B, the number of students in each room is same.


a – 10 = b + 10


a – b = 20 ----- (1)


Also, if 20 candidates are sent from B to A, the number of students in A is double the number of students in B.


a + 20 = 2(b – 20)


a – 2b = -60 ------- (2)


Subtracting eq2 from eq1


a – b – a + 2b = 20 + 60


b = 80


Thus, a = 80 + 20 = 100


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