PROBABILITY

Probability is the measure of how likely an event is

Experiment is a situation involving chance or probability that leads to results called outcome

Outcome / Sample point is the result of a single trial of an experiment

Sample space / Event all possible outcomes of an experiment (s)

In order to measure probabilities, mathematicians have devised the following formula for finding the probability of an event :

FORMULA

P(A) = the number of ways 'A' can occur
            total number of possible outcome

P ; Probability
A ; Event

0 = will not be less than 0, (impossible)
1 = will not be more than 1, (certain)

The word AND in probability means the intersection of 2 events

AND = n
OR = u

P( E n F)

E = rolling an even number
F = rolling a number greater than 3


The word OR in probability means the union of 2 events

P(E u F)


ADDITION RULE

- For any two events E and F

P ( E u F ) = P(E) + P(F) - P( E n F)

ADDITION RULE FOR MUTUALLY EXCLUSIVE EVENTS

if E and F are mutually exclusive events,

P( E u F) = P( E ) + P( F )