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A hotel has three clevators. One of themis a freight elevator. When pressing thebutton, one of the elevators randomlyservices your floor. If you use theclevators six times, what is the probabilitythat you use the freight elevator at leasttwo times?

1 Answer

7 votes

You take into account that the probability of getting the freight elevator in one case. Such a probabilty is given by:

p = 1/3 because there are three elevator

For the case in which you use the elevator six times, the probability of getting the freight elevator will be:

P = 2/(3*6) = 2/18 = 1/9

where it is taken into account that the total number of moments in which the elevator is used.

User Leang Socheat
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