Page 81 - Fixtures

@ @pbjïØ Üa@ @VV

4! = 24 {A, B,C, D}
A
)A
C B(
D

BADC BDAC BCDA
CADB CDAB CDBA
DABC DCAB DCBA

.9

()
: (derangements)

23541 12345 23514 1,2, 3,…,n
n
. .
15
.n !  1 − 1 + 1 − 1 + + (−1)n 1 
 1! 2! 3! n! 

( )

. 4! 1 − 1 + 1 − 1 + 1  = 9
1! 2! 3! 4!

()