Suppose when a baseball player gets a hit, a single is twice as likely as double which is twice as likely as a triple which is twice as likely as a home run. Also, the player's batting average, i.e., the probability the player gets a hit, is .300. Let B denote the number of basses touched safely during an at-bat. For example, B=0 when the player makes an out. B=1 on a single, and so on. What is the PMF (probability mass function ) of B?