MathDB
2014 Combinatorics #1: Probability Same Class

Source:

February 23, 2014
probability

Problem Statement

There are 100100 students who want to sign up for the class Introduction to Acting. There are three class sections for Introduction to Acting, each of which will fit exactly 2020 students. The 100100 students, including Alex and Zhu, are put in a lottery, and 60 of them are randomly selected to fill up the classes. What is the probability that Alex and Zhu end up getting into the same section for the class?