Casio FX 65 - Manual (Page 7)

FX 65 Training guide
Probability
Random number generation
[SHIFT] [RAN#] Generates a random number between 0 and 0.999.
Permutations and combinations
[SHIFT] [nPr] A permutation is a selection of objects in which the order matters.
Example: To determine the number of possible different
arrangements using 4 items selected from 10 items.
[10] [SHIFT] [nPr] [4] [=] 5040
[SHIFT] [nCr]
A combination is a selection of objects from a collection and order
is irrelevant.
Example: To determine the number of different combinations of 4
items selected from 10 items. [10] [SHIFT] [nCr] [4] [=] 210
Factorials
[SHIFT] [x!] Calculates the factorial of a number. Example: [5] [SHIFT] [!]
7
References the Casio FX-65 User’s Guide Casio FX-65 Fraction calculator