Let R=\(1,2),(2,3),(3,3)\ be a relation defined on the set \1,2,3,4\. Then the minimum number of elements, needed to be added in R so that R becomes an equivalence relation, is:
- 9
- 8
- 7
- 10
Answer
(3) 7
Solution
Equivalence = reflexive + symmetric + transitive. 1 2 3 puts 1,2,3 in one class; 4 is alone.
[figure]
Smallest relation =\1,2,3\ \1,2,3\ \(4,4)\ has 9+1=10 pairs
Already present: 3 add 10-3=7
Answer: (3)