Probability Flashcards
1
Q
How may ways can I arrange N, taking R at a time
A
Use P
N P R
2
Q
What is a permutations
A
An arrangement of a number of objects in a DEFINITE order
3
Q
What is a combination
A
A selection of a number of objects in any order
4
Q
How do I choose R objects from N different objects
A
Use choosing C
N choose R
5
Q
N choose n
A
1
6
Q
N choose 0
A
1
7
Q
Relative frequency
A
Number of times event happens in trial divided by total number of trials
8
Q
When are events mutually inclusive
A
EnF is not = 0
Ie there is an overlap in events
9
Q
Mutually inclusive theory
A
P(EuF) = P(E) + P(F) - P(EnF)
10
Q
Probability of A given that B has already occurred
A
P(AnB) divided by P(B)
11
Q
Prove events are independent
A
P(AnB) = P(A) x P(B)
12
Q
If p is the probability of an event happening then the probability of the event not happening =
A
1 - p
