Two marbles are drawn one after the other with replacement from a bag that contains: 9 red marbles, 8 blue marbles, and 3 green marbles.
Find the probability of the following events.
(a) One red marble and one green marble are drawn in either order.
(b) Two blue marbles are drawn.
(c) At least one marble is drawn that is not blue.
(d) The second marble is green if we know that the first marble is green.
a. The probability of drawing a red then a green is 9/20 * 3/20= 27/400 and the probabiltiy of drawing a green then a red is 3/20 * 9/20= 27/400 so the probability of drawing a read and a green in any order is 27/400 + 27/400= 27/200.
b. The probabilty of drawing a blue then another blue is 8/20 * 8/20= 1/25. Order doesn't matter in this case because they are the same color.
c. I'm not sure...
d. If the first marble is green, the you replace it back into the bag meaning the probability of drawing a second green is 3/20.