There are two classrooms A and B containing students. If 5 students are shifted from room A to room B, the resulting number of students in the two rooms are equals. If 5 students are shifted from room B to room A becomes double the number of students left in room B. Find the original number of student in the two rooms separately

Question

$(A) \; A:40 , B:31 \\(B)\;A:30,B:21 \\(C)\; A : 35,B:26 \\(D)\;A:28,B:34$