Question

If A = {1, 3, 5, 7, 9} and B = {2, 3, 5, 7}, what is \[{\text{A}} \cup {\text{B}}\]?
A. {3,5,7}
B. {2,3,5,7}
C. {2,3,5,7,9}
D. {1,2,3,5,7,9}

Answer 1

Hint: In order to solve this problem we need to know that U sign denotes union between two sets. The union (denoted by ∪) of a collection of sets is the set of all elements in the collection.

Complete step-by-step answer:
We have A = {1, 3, 5, 7, 9} and B = {2, 3, 5, 7}.
We need to find \[{\text{A}} \cup {\text{B}}\].
We know U denotes union between two sets.
The union (denoted by ∪) of a collection of sets is the set of all elements in the collection. It is one of the fundamental operations through which sets can be combined and related to each other.
So, \[{\text{A}} \cup {\text{B}}\]= {1, 2, 3, 5, 7, 9}.

Note: Whenever you face such types of problems with sets you need to know that U denotes union of sets and $ \cap $ denotes intersection of sets. The union (denoted by ∪) of a collection of sets is the set of all elements in the collection. From this information we will get the right solution to this question.