Venn Diagrams © 2006, Mr. C. Burke. All rights reserved.

Venn Diagrams Venn diagrams show the relationships between two sets of data. Two sets intersecting. A set and subset.

The Intersection of 2 Sets of data A class has 20 students. –12 students are boys. –10 students wear glasses. –7 are boys that wear glasses Boys Glasses Boys Glasses Both

Fill in all the sections If 7 of the 12 boys wear glasses, that means that 5 of them don’t. If 7 students that wear glasses are boys, that means that 3 of them are not. 7 Boys Glasses Both

Venn Diagrams How many of the 20 students are represented in the Venn diagram? How many of the 20 students are not shown? What do we know about those other students? 7 Boys Glasses Both 53

Venn Diagrams We can figure out that there are 5 remaining students, and they are Girls who Don’t wear glasses. 7 Boys Glasses Both Students

Example Try this example in your notebook: A used car lot has 32 cars. –18 of them are red. –12 are mini-vans. –4 are red mini-vans. How many cars are neither mini-vans nor red? Fill in the table to find your answer.

Label the diagram Try this example in your notebook: A used car lot has 32 cars. –18 of them are red. –12 are mini-vans. –5 are red mini-vans. How many cars are neither mini-vans nor red? Mini- vans Red Cars Both Start by labeling the table.

Fill in the table – Start in the center Try this example in your notebook: A used car lot has 32 cars. –18 of them are red. –12 are mini-vans. –5 are red mini-vans. How many cars are neither mini-vans nor red? Fill in the table to find your answer. Mini- vans Red Cars Both 5 Next, fill in the data that you know. Start in the middle if you can.

Answer Try this example in your notebook: A used car lot has 32 cars. –18 of them are red. –12 are mini-vans. –5 are red mini-vans. How many cars are neither mini-vans nor red? Answer: Seven cars are neither red nor mini-vans. Mini- vans Red Cars Both Then fill in the rest of the table.

One More Problem Try this example in your notebook: A class of 50 students took a Math and a Science test. –30 students passed the Math test. –25 passed the Science test. –10 passed both. How many failed both tests? Fill in the table to find your answer. Write your answer in a complete sentence.