Answer: 2^(n(n+1)/2).
- A 2^(n(n+1)/2)
- B 2<sup>n² − n</sup>
- C 2<sup>n²</sup>
- D n!
Correct answer: A. 2^(n(n+1)/2)
Explanation: Choices are made on the n diagonal entries plus the n(n−1)/2 unordered off-diagonal pairs, totalling n(n+1)/2 free binary choices.
Concept context
Types of relations, equivalence classes, one-one and onto functions, composition, and invertible functions