M = {2, 3, 5, 7} (and possibly includes 11 if "between x and y" means to include both x and y)
N = {1, 2, 3, 4, 6, 12}
Then
M U N = {1, 2, 3, 4, 5, 6, 7, 12}
(or possibly {1, 2, 3, 4, 5, 6, 7, 11, 12})
M ∩ N = {2, 3}
