The time patrons at the Grande Dunes hotel in the Bahamas spend waiting for an elevator follows a uniform

The time patrons at the Grande Dunes hotel in the Bahamas spend waiting for an elevator follows a uniform distribution between 0 and 3.5 minutes.

A. Show that the area under the curve is 1.00?
B. How long does the typical patron wait for elevator service?
C. What is the standard deviation of the waiting time?
D. What percent of the patrons wait for less than a minute?
E. What percent of the patrons wait for more than 2 minute?