# Thread: What would be the probabilities for six elevators to reach the ground floor?

1. ## What would be the probabilities for six elevators to reach the ground floor?

Let's suppose I am on the ground floor in front of six elevators.

There are 17 floors in that building including ground floor. The floors are [14,13,12,11,10,9,8,7,6,5,4,3,2,1,0,-1,-2]

Elevator #1 is on the 14th floor,
Elevator #2 is on the 10th floor,
Elevator #3 is on the 8th floor,
Elevator #4 is on the 6th floor,
Elevator #5 is on the 3rd floor and
Elevator #6 is on -2nd floor below the ground floor.

All the elevators start at the same time from the static state toward the ground floor. It takes 1 second to reach a floor.

Now, what are the probabilities for each elevator to reach the ground floor (we don't know any interruptions happened during the journey for each elevator or not but if no interruptions happened what would be the probabilities)?

2. ## Re: What would be the probabilities for six elevators to reach the ground floor?

if there are no interruptions during any given car's descent why would the probability of reaching the ground floor not be 1?

3. ## Re: What would be the probabilities for six elevators to reach the ground floor?

Originally Posted by romsek
if there are no interruptions during any given car's descent why would the probability of reaching the ground floor not be 1?
Okay, I understand that. But if we didn't know if any given elevator will reach the ground floor or not without interruption then what would be the probability?

4. ## Re: What would be the probabilities for six elevators to reach the ground floor?

Originally Posted by x3bnm
Okay, I understand that. But if we didn't know if any given elevator will reach the ground floor or not without interruption then what would be the probability?
this is basically a queuing theory problem but you've given us no description of the probabilities that people appear on given floors and need the elevator.

you've also given no description of the algorithm the elevator uses when service requests are present.

5. ## Re: What would be the probabilities for six elevators to reach the ground floor?

Originally Posted by romsek
this is basically a queuing theory problem but you've given us no description of the probabilities that people appear on given floors and need the elevator.

you've also given no description of the algorithm the elevator uses when service requests are present.
So I get it now. I have to put some constrictions. Thank you for pointing that out.

6. ## Re: What would be the probabilities for six elevators to reach the ground floor?

Have a look at this