Probability If an experiment has equally likely outcomes, then the likelihood (probability) of a particular event (A) occuring is P(A) = n(A) = Number of outcomes in which A occurs
n(U) Total number of possible outcomes
Sample Space: every possible outcome
ex. If we toss a fair coin twice, the sample space is
HH, HT, TH, TT
.
1
A fair die is thrown. What is the probability of observing: a) a multiple of 2
b) an odd number
c) an odd, multiple of 3
d) an odd, multiple of 2
e) at least a 2
.
2
From an urn containing 14 marbles of which 4 are blue and 10 are red, a marble is selected at random. What is the probability that a) the marble is blue
b) the marble is not blue
3
A 16 sided dice is thrown. What is the probability of observing:
a) a number that is divisible by 3 or 5
b) a number that is divisible by 3 and 5
4
A fair die is thrown twice. Find the probability that the sum is 8.
Sample Space
1
2
3
1
4
5 6
2
3
4
5
6
.
5
A
B
A
B
6
A
A
B
B
7
8
A
B
A
B
A
B
9
A
B
10
11