Prob (first selecting purple marble) = 7/9
Prob ( then selecting a white marble) = 2/8 = 1/4 (Note there are 8 marbles left after the first draw).
As these 2 events are independent we multiply probabilities:-
Prob( purple then white marble) = 7/9 ^ 1/4 = 7/36 (answer)
b. By a similar reasoning
Prob (2 whites) = 2/9 * 1/8 = 2/72 = 1/36 (answer)
c. Prob( getting 2 purples in a row) = 7/9 * 6/8 = 7/12
Now prob ( 2 whites) is 1/36 as we see in part b . Therefore there's a greater chance of drawing 2 purples than 2 whites.
