The hotel occupancy is 75%.
Explanation:
If a hotel has 200 guestrooms, an occupancy of 100% will naturally be 200 guestrooms being full. 1% of the rooms will be represented by two rooms, meaning that a single room represents 0.5%. Based on this we can easily claculate the occupancy of the hotel with only knowing the number of rooms that are occupied.
In this case, the GM has told Dr. Ricci that 150 out of 200 guestrooms are occupied, thus 50 rooms are empty. Since one guestroom reprresents 0.5% of the total number of rooms we just need to multiply the number of rooms available with the percentage that each room represents:
50 x 0.5 = 25
So we get a result of 25, meaning that 25% of the rooms are free, while 75% of the rooms are occupied, so the occupancy is 75%.
