http://www.ck12.org Chapter 16. Logic and Set Theory
Vocabulary
Asetis a collection of numbers, letters or anything.
Asubsetis a collection of objects within a larger set.
Set theorystudies the relationships of sets and subsets.
Aconditional statementis a statement that can be written as anif-then statement.
The “if” part of an if-then statement is called thehypothesis, antecedentorprotasis.
The “then” part of an if-then statement is called theconclusion, consequentorapodosis.
Guided Practice
- Consider the four possible scenarios of the following statement and explain why there is only one way the
statement is false.
If Brian is promised cookies then Brian will eat cookies soon. - If all of the following statements are true, what can you conclude?
- All babies are cute.
- Laura likes cute people.
- Laura is a baby.
- There are 53 people in the marching band and 49 people on the swim team. If 84 people belong to either or both
teams, how many people are on both teams?
Answers: - Scenario A –both hypothesis and conclusion are true. Brian is promised cookies and then later eats cookies. Life
is as it should be so the statement is true.
ScenarioB–hypothesis is true but the conclusion is false. Brian is promised cookies, but he does not end up eating
cookies. Life is tough for Brian. The statement is false in this case.
ScenarioC–hypothesis is false but the conclusion is true. Brian is never promised cookies, but he’s lucky and gets
to eat some anyways. The statement is true.