2. 2025 (65/2/1)

Case Study Challenge

Debate Competition: Mapping Speakers & Judges

A school is organizing a debate competition with participants as speakers
S = {S₁, S₂, S₃, S₄} and these are judged by judges
J = {J₁, J₂, J₃}.

Each speaker can be assigned one judge. Let R be a relation from set S to J defined as
R = {(x, y) : speaker x is judged by judge y, x ∈ S, y ∈ J}.

Answer the following based on the above:

(i) How many relations can be there from S to J? [1 Mark]
(ii) A student identifies a function from S to J as f = {(S₁, J₁), (S₂, J₂), (S₃, J₂), (S₄, J₃)}. Check if it is bijective. [1 Mark]
(iii) (a) How many one-one functions can be there from set S to set J?

— OR —

(b) Another student considers a relation R₁ = {(S₁, S₂), (S₂, S₄)} in set S. Write minimum ordered pairs to be included in R₁ so that R₁ is reflexive but not symmetric.

[2 Marks]