15 different balls are distributed to 4 people, and each person has at least 1 ball, which is equivalent to inserting 3 separators in 14 interval between 15 elements, and c (14,3) =14 *. =364 points.

15 Different balls are distributed to 4 people, and the number of balls distributed to each person is unlimited. 4 points for each ball, * *15 =1073741824, 4 points.