Set A and Set B is the numbers that are in both Set A (1, 2, 3, 4, 5, 6, 7, 8, 9) and Set B (2, 4, 6, 8). Set B and Set C is the numbers that are in both Set B (2, 4, 6, 8) and Set C (4, 8). Set B or Set C is the numbers that are in Set B (2, 4, 6, 8) or Set C (4, 8).