Statement : All hotels are rooms. All rooms are flats. All flats are buildings. No building is apartments. Conclusion : Some buildings may not be rooms. Some apartments are not flats. Some apartments are flats. All hotels are buildings.

all rooms are flats (A) + All flats are buildings (A) → All rooms are buildings (A) → Conversion → some buildings are rooms (I) → probable conclusion → Some buildings may not be rooms (I). Hence, Conclusion I follows. All flats are buildings (A) + No building is an apartment (E)→ No flat is an apartment (E) → Conversion → Some apartments are not flats (O). Hence, conclusion II follows but Conclusion III does not follow. All hotels are room (A) + All rooms are flats (A) → All hotels are flats (A) + All flats are buildings (A) → All hotels are buildings. Hence, Conclusion IV follows.