There are 50 states in the United States, and each state is represented by 2 senators in the U.S. Senate. A group of 20 U.S. senators is chosen randomly from the 100 senators in the U.S. Senate to visit a troubled part of the world.
a. What is the probability that the two Massachusetts senators are among those chosen?
b. What is the probability that neither of the two Massachusetts senators is among those selected?