This cat riddle sounds as though it might require a lot of animals, but the room itself gives away the answer.
There is one cat in each corner of a room. A normal room has four corners, so there are four cats. Each cat can see the other three cats from its own corner.
Answer: 4 cats.
No extra cats are needed for every cat to see three others. The same four cats satisfy both clues at once. The trick is avoiding the temptation to count three additional cats for every corner.


