Download presentation

Presentation is loading. Please wait.

Published byHannah Palmer Modified over 4 years ago

1
Can you think of five famous people who you feel are rational/logical?

2
Deciding whether a syllogism is valid Trying to decide if a syllogism is valid is not easy. Venn diagrams can help (at last a good use for Venn diagrams!)

3
Deciding whether a syllogism is valid Some IB students are from Russia All Russians are good at drinking vodka Therefore some IB students are good at drinking vodka Is this a valid argument? Mmmmmm m…Vodka!

4
Using Venn diagrams Some IB students are from Russia IB Students Russians IB Students who are Russian

5
Using Venn diagrams All Russians are good at drinking vodka IB Students Russians Good vodka drinkers

6
Using Venn diagrams Therefore some IB students are good at drinking vodka IB Students Russians Good vodka drinkers

7
Another example All As are Bs All Bs are Cs Therefore all Cs are As

8
Another example All As are Bs A B

9
Another example All Bs are Cs A B C

10
Another example Therefore all Cs are As A B C These Cs are not As The syllogism is not valid

11
Another example! All As are Bs Some As are Cs Therefore some Bs are Cs

12
Another example! All As are Bs A B

13
Another example! Some As are Cs A B C

14
Another example! Therefore some Bs are Cs A B C The syllogism is valid

15
Now your turn Using Venn diagrams in your notebooks, decide whether each of the following arguments is valid or invalid.

16
Valid or invalid All Norwegians eat hotdogs Edward eats hotdogs Therefore Edward is Norwegian

17
Valid or invalid No Swedes have red noses Mr Luitjens has a red nose Therefore Mr Luitjens is not a Swede

18
Valid or invalid All IB1 boys are brave Some brave people are compassionate Some IB1 boys are compassionate

19
Valid or invalid Some physicists are frauds Some frauds are not wealthy Therefore some physicists are not wealthy

20
Valid or invalid All Norwegians have dogs No good football players have dogs Therefore no Norwegians are good football players

21
Valid or invalid All clever girls are red-headed All red heads are rich Therefore all clever girls are rich

22
Valid or invalid No teachers are clever No IB1 students are clever Therefore no IB1 students are teachers

Similar presentations

Presentation is loading. Please wait....

OK

#tbt #4 Who Owns The Zebra?

#tbt #4 Who Owns The Zebra?

© 2018 SlidePlayer.com Inc.

All rights reserved.

To make this website work, we log user data and share it with processors. To use this website, you must agree to our Privacy Policy, including cookie policy.

Ads by Google

Ppt on obesity prevention programs Ppt on business etiquettes Ppt on acid-base indicators in nature Ppt on college management system Ppt on division for class 3 Ppt on acid-base indicators colors Ppt on single phase and three phase dual converter Ppt on introduction to production and operation management Ppt on point contact diodes Ppt on foldable screen technology