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 equal. If 5 students are shifted from room B to room A,the number of students in room A becomes double the number of students left in room B. Find the original number of students in the two rooms separately

Question

$a) \; A:40 , B:31 \\b)\;A:30,B:21 \\c)\; A : 35,B:25 \\d)\;A:28,B:34 $