Answer:
Probability states the ratio of number of favorable outcomes to the total number of possible outcomes.
i.e,

A bag contains:
Brown marble = 4
Green marbles = 3
Red marbles = 2
Purple marble = 1
Total number of possible outcomes = (4+3+2+1) = 10 marbles
P(Brown marbles) =

P(Green marbles) =

P(Red marbles) =

and
P(Purple marbles) =
