Question

Assume a jar has 7 red marbles and 5 black marbles. Draw out 3 marbles with and without replacement. Find the requested probabilities.
(a) P(3 red marbles)
With replacement , without replacement .

(b) P(3 black marbles)
With replacement , without replacement .

(c) P(one red and two black marbles)
With replacement , without replacement .

(d) P(red on the first draw and black on the second draw and black on the third draw)
With replacement , without replacement .

Answer 1

12 marbles altogether

Answer 2

slow computer today....

Answer 3

these are the answers i got do you know if they are right?
a) with 343/1728 without 21/132

Answer 4

b)with 125/1728 with out 60/132

Answer 5

c) I did not know how to do
d) with 175/1728 without 14/132

Answer 6

with replacement should be:

12!
--- or some such formula...
7!

Answer 7

i think its 7/12*7/12*7/12