The number of reflexive relations on a set containing n elements is:

The number of reflexive relations on a set containing n elements is:

• A. 2^(n²)
• B. 2^(n(n−1))
• C. 2^(n(n+1))
• D. n²

Answer: B) 2^(n(n−1))

Explanation: A relation is a subset of A × A. For it to be reflexive, it must contain all n diagonal elements. The remaining n² − n elements can either be in the relation or not. Ways = 2^(n²−n) = 2^(n(n−1)).