What is the union of the citizens of England, Scotland, Wales and Northern Ireland?

Primary tabs

Lesson Parent: 
The Union and Intersection of Sets
Problem: 

What is the union of the following four sets:
\begin{eqnarray}
E&=&\{x:\,x\mbox{ is a citizen of England}\}\\
S&=&\{x:\,x\mbox{ is a citizen of Scotland}\}\\
W&=&\{x:\,x\mbox{ is a citizen of Wales}\}\\
N&=&\{x:\,x\mbox{ is a citizen of Northern Ireland}\}.\\
\end{eqnarray}

Answer: 

The United Kingdom of Great Britain and Northern Ireland

SAMPLE SOLUTION

All of our problems have fully worked out, logical solutions. We connect every solution to its underlying lesson so you can understand the concepts needed to solve any problem and reinforce your learning by practicing with similar problems. All of the formulas are available to our subscribers, but here is a sample of the problem solution you will see when you log in:



Solution: 

The point of this problem is that we can expand the concept of union (and intersection) to more than two sets. We will write a lesson on this at some point, but the idea here is that

<Sign in to see all the formulas>

The set of all the people that are citizens of one of these countries is the United Kingdom of Great Britain and Northern Ireland.