70 likes | 169 Views
Chapter 9. Logic. Problem. Three dogs called Lassie, Timmy and Fido have either black, brown or tri-colour hair. The dogs have lived with their owners for either 9 months, 2 years or 7 years. The dog who has lived with their owner the longest has brown hair.
E N D
Chapter 9 Logic
Three dogs called Lassie, Timmy and Fido have either black, brown or tri-colour hair. The dogs have lived with their owners for either 9 months, 2 years or 7 years. • The dog who has lived with their owner the longest has brown hair. • Fido has lived with his owner for longer than Lassie. • Fido does not have tri-colour hair and Lassie does not have black hair. How long has each dog lived with its owner and what colour hair does it have?
TOK All students observed entering the maths studies class are girls. Therefore, all maths studies students are girls. All students in this class are studying maths studies. Alix is in this class. Therefore Alix is studying maths studies. Deductive Logic Inductive Logic Which is better?
This is the negation of p, so it’s the opposite of whatever is in p. This is the conjunction (intersection) of p and q. It is true only when both p and q are true. This is an implication, ‘p implies q’. It is true whenever p is false or when both p and q are true. These are the two original propositions and the different combinations of ‘true’ and ‘false’ possible. This is the disjunction (union). It is true unless both both p and q are false. This is the exclusive disjunction, which means it is one or the other but not both. This is equivalence. It is true when either both propositions are false or both are true.