Other Functions; Factorial N!, Permutations And Combinations - LEXIBOOK SC460 Owner's Manual

Factorial n!, permutations and combinations

[SHIFT] [n!]
[NCr]
[SHIFT] [nPr]
As a reminder
The factorial of n! or factorial n! represents the following value:
n! = 1 x 2 x 3 x.....x (n-2) x (n-1) x n
n! represents the number of different ways that n different objects can
be rearranged (n! permutations).
When we choose r elements between these objects:
• The number of combinations, in other words, the number of different
possibilities of choosing r elements among these n objects, is :
• If we can arrange them in r ways the possible number of distinct
permutations is:
E.g.:
8 horses are participating in a race. How many possible combinations of their
order of arrival are there?
How many possible combinations of the winning combination of the first three
horses are there in any given order?
How many possible combinations of the winning combination of first three
horses are there in the correct order?
What are my chances of finding the winning combination of the first three
horses in the correct order, or in any given order?
Number of permutations of their order of arrival = n! where n = 8.
8 [SHIFT] [n!] [=] -> 40,320.
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6. OTHER FUNCTIONS

Calculation of the Factorial n!
Your calculator allows you to calculate the Factorial n! up
to n=69 (see chapter on "Error Messages")
Calculates the number of possible combinations (see below)
Calculates the number of possible permutations (see below)
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20/6/07 15:28:13