42. More than 50 million guests stayed at bed and breakfasts (B&Bs) last year. The Web site for the Bed and Breakfast Inns of North America (http://www.cimarron.net), which averages approximately seven visitors per minute, enables many B&Bs to attract guests without waiting years to be mentioned in guidebooks (Time, September 2001).

a. Compute the probability of no Web site visitors in a one-minute period.

b. Compute the probability of two or more Web site visitors in a one-minute period.

c. Compute the probability of one or more Web site visitors in a 30-second period.

d. Compute the probability of five or more Web site visitors in a one-minute period.