In a hotel, four rooms are available. Six persons are to be accommodated in these four rooms in such a way that each of these rooms contains at least one person and at most two persons. Then the number of all possible ways in which this can be done is ______. [2020]
(1080)
Groups can be possible in only 2, 2, 1, 1 way.
Number of ways of dividing persons in group
Number of ways after arranging rooms