Abuilding contains two elevators, one fast and one slow. the average waiting time for the slow elevator is 3 min. and the average waiting time of the fast elevator is 1 min. if a passenger chooses the first elevator with probability 2 3 and the slow elevator with probability 1 3 , what is the expected waiting time?

Which of the following would be a correct step in proving that triangle abc is congruent to triangle cda? a. use a protractor to measure the angles and show that all the corresponding angles are equal in measure. this will allow you to prove congruence by aaa. b. show that segment ab is parallel to segment cd and segment ad is parallel to segment cb. this will allow you to prove congruency by asa. c. show that is segment ab is perpendicular to segment ad. this will allow you to prove congruence by sas. d. none of the above.