27. Suppose that an um contains n balls all of which are white except one which is red. The urn is thoroughly mixed and all the balls are drawn from the urn without replacement by a blindfolded individual. Show that the probability that the red ball will be drawn on the kth draw is l. 28. Two people each toss a coin n times that lands heads with proba- bility 1/3. What is the probability that they will each have the same number of heads? What is the probability if the coin lands heads with probability 1/4