Question

A group of m people simultaneously enter an elevator at the ground floor. Each person randomly chooses one of the r floors 1, 2, . . . , r as the exit floor, where the choices of the persons are independent of each other. The elevator only stops on a floor if at least one person wants to exit on that floor. No other people enter the elevator at any of the floors 1, 2, . . . , r. What are the expected value and the standard deviation of the number of stops the elevator will make?

Answer 1

Answer:

Sorry can't help with this question