Suppose we flip a fair coin repeatedly. Let Xi equal 1 if flip i was heads (H) and 0 otherwise. Let N denote the number of flips needed until H has occurred 100 times. Is N independent of the random sequence X1, X2, . . .? Define Y= X1 + ∙ ∙ ∙ + XN. Is Y an ordinary random sum of random variables? What is the PMF of Y?