Consider the ways that the letters in the word "Mississippi" can be rearranged (the 4 i's are indistinguishable, the 4 S's are indistinguishable, and the 2 P's are indistinguishable).
a. What is the probability that the S's are grouped together?
b. What is the probability that the S's are grouped together and the P's are grouped together?
c. What is the probability S is the 1st letter and I is the 5th letter?
d. What is the probability S or P is in the 1st spot?