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 0,1,2,3,4,5,or 6.The probabilities are the same for each of these (1/7) .If X is the number of calls arriving in a five-minute time period,what is the mean of X?

A) 2
B) 3
C) 4
D) 5
E) None of the above