A U B is the set of elements which are in A, in B, or in both A.
Since,
A = {2, 3, 6}
B = {2, 4, 5, 7}
To find A U B, we have to write all numbers that are in A and/or in B. The number that are in both sets must not be written again.
A U B = {2, 3, 6, 4, 5, 7}
Writing then in acending order:
A U B = {2, 3, 4, 5, 6, 7}
Answer: A U B = {2, 3, 4, 5, 6, 7}.
