Quantified Statements Flashcards
(15 cards)
Most (Definition)
Indicate that more than 1/2 of the group have a certain property.
Most As are Bs
51% to 100%
Cannot reverse
Cannot take contrapositive
(Must be true, Parellel, Sufficient Questions)
Negate “Most”
At least half… not
0-50%
All
100%
Normal conditional statement
Cannot reverse
Contrapositive is always valid
(Must be true, Parellel, Sufficient Questions)
Some (Definition)
At least 1 member of a group has certain property
Some As are Bs
Are reversible
Don’t always have valid contrapositive
(Must be True, Parellel, Sufficient Questions)
Negate “Some”
None
None
0
Negate “None”
At least 1
Negate “All”
0-99%
Not all…
Some…
Diagram an “All” statement
A—>B
/B—>/A
Diagram an “Most” statement
A-m->B
Diagram an “Some” statement
A-s-B
B-s-A
Combine
All + Some Statement
Shared term is the sufficient condition of the All statement, results in a “some” statement using the other two terms
A—>B
A-s-C
———
B-s-C
Two Most Statements
Shared term is the sufficient condition of both “Most” statements; results in a “some” statement using the other two terms
A-m->B
A-m->C
———
B-s-C
All + Most Statements
TWO valid ways:
1. Shared term is the sufficient condition of the “All” & “Most” statements; results in a “Some” statement using other two terms
A—>B
A-m->C
———-
B-s-C
- Shared term is the necessary condition of the “Most” statements & the sufficient condition of the “All” statement; results in a “Most” statement using the other two terms
A-m->B
B—>C
———
A-m->C
Quantified Statements that can never be validly combined
Most + Some
Some + Some