Elevators

I needed to get up to the ninth floor in a 24 floor building today. I was warned ahead of time that only one of the six elevators actually goes to the ninth floor. When I got to the lobby I found a crowd of people waiting for each of the six elevators. I asked one lady which one will take me to the 9th floor...she pointed in the other direction. So I went to another elevator and asked another lady, who then pushed her way to the front to show me the small sign listing which floors each elevator goes to. That elevator only went to floors 2, 4, 6, 8, and 10. The lobby finally cleared as the crowd made its way into their respective elevators. I found the one elevator that went to floor nine, only to realize that it was out of service! I hopped on the elevator that took me to the eighth floor and found a set of stairs to get me to the ninth floor. I felt like I had solved a complex math problem....or maybe this is Frogger II: the elevator challenge.