A forest contains 20 elks, of which 5 are captured, tagged and then released. A certain time later, 4 of the 20 elks are captured. What is the probability that 2 of these 4 have been tagged? What assumptions are made?
p= (5/2)x(20-5/2)/(20/4)
It is assumed that all possibilities of selecting 4 out of 20 elks are of equal probability.
