Suppose that an urn contain 8 red balls and 4 white balls . We drawn 2 balls from
the urns without replacement (a) If we assume that each draw , each ball in the urn
is equally likely to be chosen , what is the probability that both balls drawn are red
? (b) Now suppose that the balls have different weights, with red ball having weight r
and each white ball having weight w . suppose that the probability that a given ball
in the urn is the next one selected is its weights divided by the sum of the weights of
all balls currently in the urn . Now what is the probability that both balls are red?
