Texas Instruments TI-30X IIS - Page 78

© 1999 T
EXAS
I
NSTRUMENTS
I
NCORPORATED
TI-30X ÙS: A Guide for Teachers
71
Using the digits 1, 3, 7, and 9 only
one time each, how many 4-digit
numbers can you form?
4! = x
1379
ABCD
H
ABCD
BACD
CABD
DABC
ABDC
BADC
CADB
DACB
ACBD
BCAD
CBAD
DBAC
ACDB
BCDA
CBDA
DBCA
ADBC
BDCA
CDAB
DCAB
ADCB
BDAC
CDBA
DCBA
Press Display
4 H " "
nPrnPr nCrnCr ! !
&
--
DEG
< <
4! 4!
'
24.24.
DEG
Factorial (!)