15-1 Venn Diagrams

So I guess this week, I'll teach you how to work problems using venn diagrams. They are really easy. The good thing about this week is that venn diagrams don't have that many notes. So I guess I should get started.

First, there are a few things you need to know:

1. The intersection= n (which is the middle of the two circles)
2. The union=u (which is all of the two circles)
3. The complement is when there is a line over the letter. This means you want all elements that are not whatever is under the line.
4. You might also need to know this formula: n(A u B)=n(a) + n(b) - n(A n B)
5. That formula is so you don't count the middle number twice. It is very important that you don't count the middle twice! So don't forget that!

Okay, so now I am going to work an example. WOOO!

Example 1: Given the diagram below find (F n M), (F u M), and the complement of F.

Okay, well it isn't letting me download a picture on hereee. So I am just going to have to explain what it looks like.

1. The first circle is F and it has 285.
2. The other circle is M and it has 50.
3. The middle of the two circle is 15.
4. The left over is 650.
5. The overall number of the diagram is 1000.

• (F n M)= 15. Remember that when it is n it is always what's in the middle.
• (F u M)= 350. Thats all the circles added up, including the middle.
• The complement of F is everything except for F, which is 700.

Well, that's it for this weeek. BYEE :)

--Halie