In a school of students

MATHEMATICS · Multi-part · CBSE · Mathematics · Relations and Functions · Relations and Functions

Problem

In a school of 180180 students, each student belongs to exactly one of the four house colours: Red, Blue, Green, or Yellow. Define a relation HH on the set of students by P H Q  ⟺  PP\,H\,Q \;\Longleftrightarrow\; P and QQ are in the same house colour. Answer the following questions: (i) Prove that HH is an equivalence relation on the set of all students. (ii) How many distinct equivalence classes does HH produce? (iii) If 4545 students are in the Red house, determine the size of the equivalence class of any student who belongs to the Red house.

Related theory

Browse the problem library