HP 10bII+ - Combinations; Random Number and Seed

Statistical Calculations
127
Example
Using five books labeled A, B, C, D, and E, how many different ways can three books be
placed on a shelf?
Table 12-15 Example calculating permutations
Combinations
The nCr function calculates the number of different sets, or combinations, of n items taken r
at a time. No item can occur more than once in the set of r items, and different orders of the
same r items are not counted separately. This is calculated using the formula:
Example
Using five colored balls, how many different color combinations of three colors can be
chosen?
.
Random Number and Seed
The 10bII+ includes a random number generator function that generates a pseudo-random
number in the range 0 < x < 1. To store a seed value, type a positive number and press
\w]6. Storing a value of 0 will select a random number and store it as the
seed value.
Keys Display Description
V]<D4
60.00 Calculates permutations of n
items taken r at a time.
or, using Æ:
VÆD]<
60.00
COMBINATIONS
n!
nr–()!r!
----------------------=
Table 12-16 Example calculating combinations
Keys Display Description
V]9D4
10.00 Calculates combinations of n
items taken r at a time.
or, using Æ:
VÆD]9
10.00