Adding two examination rooms and reducing two examination rooms are four different from the original examination room. When two examination rooms are added and each examination room can seat 24 people, then reducing two examination rooms is equivalent to reducing four examination rooms, that is to say, four examination rooms with 4*24=96 people should be arranged in the remaining examination rooms. Because there are 30 people in each examination room, 30-24=6 people are more, so 96 people should be arranged in 96÷6= 16 examination rooms.
Formula: (2+2)×24÷(30-24)×30=480 (person)