Math
posted by Junior .
A bag contains 4 green marbles, 6 red marbles, and 2 white marbles. Three marbles are drawn at random with replacement. With replacement means that after a marble is drawn, it is replaced before the next one is drawn. What is the probability of not green, not red, not white?

p(~g) = 8/12 = 2/3
p(~r) = 6/12 = 1/2
p(~w) = 10/12 = 5/6
p(~g,~r,~w) = 2/3 * 1/2 * 5/6 = 5/18 
Not green = (6+2)/12
Not red = (4+2)/12
Not white = (4+6)/12
The probability of both/all events occurring is determined by multiplying the probabilities of the individual events.