Question

Let U= {1,2,3,4,5,6,7,8}, A={3,6,8}, B= {1,2,7,8}, and C={4,5,7}. Find the following. Use the roster method to write the set. Enter empty or 0 for the empty set.A U B

Answer 1

Given the universal set, U = {1,2,3,4,5,6,7,8}

A = {3,6,8}

B={1,2,7,8}

C = {4,5,7}

We are to find A U B

A U B is read as A union B

Let us look at what a union of a set it.

Union of the sets A and B , denoted A ∪ B , is the set of all objects that are a member of A , or B , or both.

Hence, A U B = {1,2,3,6,7,8}