The average area of 2 rooms I and II are 400 square meters. If one rectangular room(III) area is added then the average area becomes 500 square meters. If another room IV, whose area is 600 square meters more than the III room, replaces room I, then the average area of II, III and IV room becomes 900 square meters. Find the area of I room.
1
130 square meters
2
120 square meters
3
100 square meters
4
150 square meters
5
180 square meters