Assume hat every time you buy a box of Corn Flakes, you receive one of the pictures of the k players of the Florida Marlins. Over a period of time you buy n >= k boxes of Corn Flakes. Let Ej, j=1,2,3,...,k, denote the event you do not get the jth player's picture.
What is the probability of Ej?
What is the probability of Ej intersect Ei (i is just another player)?
I think once i have those I can use the inclusion-exclusion principle to answer what is the even you do not get at least one picture.