Let R1 = {(1,1), (2,2), (3,3)} and R2 = {(1,1), (1,2), (1,3), (1,4)}. Match List I with List II. List I: A. R1 ∪ R2, B. R1 − R2, C. R1 ∩ R2, D. R2 − R1. List II: I. {(1,1), (1,2), (1,3), (1,4), (2,2), (3,3)}, II. {(1,1)}, III. {(1,2), (1,3), (1,4)}, IV. {(2,2), (3,3)}.

1. AA-I, B-II, C-IV, D-III
2. BA-I, B-IV, C-III, D-II
3. CA-I, B-III, C-II, D-IV
4. DA-I, B-IV, C-II, D-III

Pick an option to check yourself, or open the answer below.

Show answer & explanation

Correct answer: D. A-I, B-IV, C-II, D-III

Explanation

The union has all six pairs; R1 − R2 removes (1,1), leaving (2,2), (3,3); the intersection is {(1,1)}; R2 − R1 is {(1,2), (1,3), (1,4)}.