15-1

Venn Diagrams

This week I'm going to reteach lesson 15-1, Venn Diagrams. In this lesson, we learned how to work problems dealing with intersections, unions, and compliments. An intersection(n) is the middle of two joined circles. A union (u) is everything within two joined circles. A compliment is represented by a line over a letter, and is everything but the amount under that letter.

*I couldn't upload a picture, so I'm going to do my best on this example without one.

Example 1: There are 1,000 total students at Oakville High. S(Students who just play sports) has 320. M(Students who just take Math) has 70. 30 students do both. 580 students don't do either. Find a) (SuM), b) (SnM), c) compliment of S, d) compliment of M, and e) compliment of (SuM)

• a) (SuM) is the union, so that would be all of the students counted inside the intersected circles. Therefore, (SuM)=420.
• b) (SnM) is the intersection, so that is the students who do both sports and Math. Therefore, (SnM)=30.
• c) The compliment of S would be all of the students who are not playing sports. So, the compliment of S=650.
• d) The compliment of M would be all of the students not taking math, so that would =900.
• e) The compliment of (SuM) would be all of the students not doing either activities. So the compliment of (SuM) = 580.