1) Is there a chair in the room. - Yes, there is a chair in the room.
2) Are there three armchairs in the room? - Yes, there are three armchairs in the room.
3) Is there a carpet on the floor? - Yes, there is a carpet on the floor.
4) Are there any flowers on the table? - No, there are no flowers on the table.
5) Are there any books on the floor? - No, there are no books on the floor.
6) Is there a desk next to an armchair? - Yes, there is a desk next to an armchair. (лучше бы the armchair, ведь речь, скорее всего, о конкретном кресле)
7) Are there any pillows on the sofa? - No, there are no pillows on the sofa.
8) Is there a window next to the table? - Yes, there is window next to the table.