4. How many different ways can you put 8 balls in 8 boxes A1, .
. . , A8
if (a) the balls are all different and no box is empty 8!
(b) the balls are all different and only three boxes A1, A2 and
A3 are empty
(c) the balls are all different and exactly four boxes are
empty
(d) the balls are all different and each box is either empty or
contains exactly two balls
(e) the balls...