The elements of sets A , B and C are all colours as follows:
A = { Red , Orange , Yellow , Brown } ,
B = { Blue , Yellow , Green , Brown } ,
C = { Black , Brown , White , Grey }
Then, A U B U C is
{ Red , Orange , Yellow , Brown , Blue , Green , Black , White , Grey }
The union of two sets is a set of all elements that are present in set A and set B.
{ Red , Orange , Yellow , Brown , Blue , Green , Black , White , Grey }