The Mongol general Subudai is expecting reinforcements from Chenggis Kahn before attacking King Bela of Hungary. The probability mass function describing the number N of tumens (units of 10,000 men) that he will receive is
If he receives N = k tumens, then his probability of losing the battle will be 2-k. This can be described by defining the random variable W which will be 1 if the battle is won, 0 if the battle is lost, and defining the conditional probability mass function
(a) Find c.
(b) Find the (unconditional) pmf pW(m), that is, what is the probability that Subudai will win or lose?
(c) Suppose that Subudai is informed that definitely N