You are scheduling carpet cleaning for each floor in a building that has 8 floors. You have the following restrictions: Floors 6 and 8 cannot be cleaned on the same day. Floors 1 and 5 cannot be cleaned on the same day. Floors 1 and 7 must be cleaned on the same day. Floor 7 must be cleaned before floor 2. Referring to the above, which floors could all have their carpets cleaned on the first day of the cleaning schedule