Question 25
There are 10 CISMO students in a classroom. It was agreed that all of the students’ cellphones will be put to silent mode and placed on the proctor’s table before the start of the examination. When the competition is over, everyone picks up a cellphone at random. What is the probability that nobody gets his/her own cellphone?
Enter an exact fraction; the source does not request rounding.
Enter an exact fraction; the source does not request rounding.