Set theory, events and probability

Question 1

what is a sample space

Answer 1

it is a set which lists all the possible outcomes of an experiment - the order is not important

Question 2

what is an event

Answer 2

it is a subset of a sample space

Question 3

what is a classical probability

Answer 3

in classical approach we make an assumption that each outcome in the sample space is equally likely

Question 4

axioms of probability

Answer 4

P(S) = 1; if A && B = 0 then P(A || B) = P(a) + P(b)

Question 5

what is permutation

Answer 5

it is the number of ways of choosing r elements out of n where the order matters: P = n!/(n-r)!

Question 6

combinations

Answer 6

that is the number of ways choosing r elements out of n where the order does not matter :
P = n!/(r!*(n-r)!)