Counting Methods
ACT · Flashcards · Recall
ACT · FLASHCARDS
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QUESTION
What is the formula for calculating combinations of
n
n
n
items taken
r
r
r
at a time?
QUESTION
Identify the rule: when choices are mutually exclusive, how do you count total outcomes?
QUESTION
What is the number of ways to choose
r
r
r
items from
n
n
n
distinct items when order does not matter?
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ANSWER
n
C
r
^nC_r
n
C
r
. Selection without regard to arrangement order.
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