Skip to content / Đến nội dung
ThichHocToan.com

PIMSO 2022 - Mathematics - Senior Secondary - National Round Question 25

PIMSO Maths · PIMSO 2022 - Mathematics - Senior Secondary - National Round

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 the exact probability as a fraction.