Odds & probabilities

Question 1

Probability

Answer 1

P(event) = A/N

A = number of times the desired event actually occurs
N = total number of trials during which A may occur

Question 2

Probability (2 events)

Answer 2

p = p(A) + p(B) - p(A+B)

Question 3

Odds

Answer 3

Odds = frequency of one event occurring / frequency of another event occurring

Probability = frequency of one event occurring / frequency of all events occurring