The Number of Phone Calls Coming into a Switchboard in the Next

Multiple Choice

The number of phone calls coming into a switchboard in the next five minutes will either be 0, 1, or 2.The probabilities are the same for each of these (1/3) .If X is the number of calls arriving in a five-minute time period, what is the mean of X?

A) 1/3
B) 2/3
C) 1
D) 4/3