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

Let initially the number of students in classroom A and B be x and y respectively.


According to question -


x - 10 = y + 10


x - y = 20.....(1)


and,


x + 20 = 2(y - 20)


x - 2y = - 60.....(2)


Subtracting equation (2) from (1), we get -


y = 80


substitute the value of y in equation (1), we get -


x = 100


Thus, No. of students in classroom A is 100 and in B is 80.


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