3 individuals take the elevator in 15-story building. What are the odds they all will get off on the same floor? Notice: they are all strangers to one another.

Question

hartnn · Answer

can u find the probability first ?

anonymous · Answer

no

anonymous · Answer

@hartnn  
can u do it?

hartnn · Answer

the probability that 1 person gets off on 'n' floor = 1/15
so the probability that all 3 get off on same 'n' floor will be  (1/15)(1/15)(1/15)
git this ?

hartnn · Answer

*got this ?

hartnn · Answer

(1/15)(1/15)(1/15) = 1/3375
take p= 1/3375
calculate odds as p/(1-p)

unklerhaukus · Answer

isn't the probability that 1 person gets off on 'floor n'  certain

unklerhaukus · Answer

there is only two degrees of freedom

anonymous · Answer

thanks @hartnn

anonymous · Answer

@hartnn  can u please tell me the final answer?

hartnn · Answer

(1/3375)/(3374/3375) = 1/3374 = 2.96 *10^-4

anonymous · Answer

sorry but these are not the options of mine

hartnn · Answer

O.o

anonymous · Answer

options are 
1/196
1/3375
1/2744
3/225

hartnn · Answer

if they are asking for chances(they might have used the word odds for chances or probability) then its 1/3375

anonymous · Answer

i also think so ... thanks for ur help

hartnn · Answer

welcome ^_^

unklerhaukus · Answer

the probability the first person gets off at stop n is 1
the probability that two people get off together at stop n is 1/15
the probability that three people get off together at stop n is 1/15 x 1/15 =1/225