What is the OA muzali ?muzali wrote:Six people are on an elevator that stops at exactly 6 floors. What is the probability that exactly one person will push the button for each floor?
Please explain your approach.
muzali well there is not such a condition that everyone will stop at different floors so
for the first floor we have 6 people,
for the second floor we have AGAIN 6 people
you know where I am going with this:
6x6x6x6x6x6 = 6^6 ways
since we are asked:
What is the probability that exactly one person will push the button for each floor?
well lets call these 6 guys 1, 2,3,4, 5, 6
so they can stop like
6 5 4 3 2 1
3 4 5 1 2 6
and etc...
So we need to find all the possible ways that ONLY one person stops at each floor
6 persons for the first floor
5 persons for the second
4 persons for the third
....
1 person for the last floor
6x5x4x3x2x1 = 6!
So Probability is : 6!/6^6
