The number of relations, on the set containing and , which are reflexive and transitive but not symmetric, is ______.
Answer: 3
Solution
A reflexive relation on must contain . With and present, transitivity forces . The only further pairs that may be added are from . Adding together with would force , and the resulting relations either break transitivity or become symmetric. Checking the cases, the relations that remain transitive and non-symmetric are the base relation, the base together with , and the base together with . There are such relations.
JEE Main · 2023 · 12 Apr 2023 · Shift 1 · Integer answer