"Bob Engelhardt" wrote in message
...
...
If I pick one marble, then pick another, the probability of drawing one
black and one white marble is 50%. (4 possibilities, 2 of which give 1
white & 1 black.)

If I reach in and pick 2 marbles AT ONCE, the probability is 33%. (3
possibilities, 1 of which gives 1 of each color.)

Bob

There are still 4 possibilities, two of which are degenerate and thus give
equivalent results.

jsw