A All roses fade quickly
B Some roses may fade quickly
C No roses fade quickly
D All flowers are roses
Explanation: Since some flowers fade quickly and roses are flowers, some roses may fade quickly.
A A
B B
C C
D Cannot be determined
Explanation: By transitivity, if A > B > C, then C is the shortest.
A It rained
B It might have rained
C It did not rain
D The ground is always wet
Explanation: This is affirming the consequent. Wet ground could have other causes besides rain.
A Yes
B No
C Not necessarily
D Only if she studied medicine
Explanation: Having a degree is necessary but not sufficient for being a doctor.
A Some cats are poodles
B No poodles are cats
C All dogs are poodles
D Some dogs are cats
Explanation: If no cats are dogs and all poodles are dogs, then no poodles can be cats.
A The sky is blue
B Water is wet
C The sky is above us
D None are conclusions
Explanation: In an argument, the conclusion is what the premises are meant to support.
A C implies A
B A implies C
C B implies A
D C implies B
Explanation: By hypothetical syllogism, if A→B and B→C, then A→C.
A All students get good grades
B Some students get good grades
C No students get good grades
D All who get good grades study hard
Explanation: Since some students study hard and all who study hard get good grades, some students get good grades.
A Some squares are rectangles
B All rectangles are squares
C No squares are rectangles
D Some rectangles are squares
Explanation: If all squares are rectangles, it\'s impossible for no squares to be rectangles.
A It was sunny
B It was not sunny
C We went to the beach
D Nothing follows
Explanation: By modus tollens, if P→Q and not Q, then not P.
A Penguins can fly
B Penguins have wings
C All animals with wings are birds
D Penguins are not birds
Explanation: All birds have wings and penguins are birds, so penguins have wings.
A Smoking causes cancer
B Cancer is bad
C Banning smoking will reduce cancer
D All of the above
Explanation: The argument assumes that banning smoking will actually reduce cancer rates.
A Some C are B
B No C are B
C All B are C
D Some B are A
Explanation: If no A are B and all C are A, then no C can be B.
A A fact
B An inference
C An opinion
D A definition
Explanation: The statement draws a conclusion about cause and effect, making it an inference.
A Tomorrow is Tuesday
B Tomorrow is not Tuesday
C Tomorrow could be any day
D Tomorrow is Monday
Explanation: Denying the antecedent doesn\'t tell us what tomorrow is.
A Copper conducts electricity
B All conductors are metals
C Some metals don\'t conduct
D Copper is not a metal
Explanation: By syllogism, copper must conduct electricity.
A Exercise is good
B John also smokes
C Healthy people exercise
D Exercise is popular
Explanation: If John also smokes, his health could be negatively affected despite exercise.
A Some X are Z
B No X are Z
C Some X may not be Z
D All X are Z
Explanation: We can only say some X may not be Z, not that no X are Z.
A Ad hominem
B Non sequitur
C Straw man
D Circular reasoning
Explanation: Being rich does not logically lead to being happy; the conclusion doesn\'t follow.
A B is false
B B is true
C Both are false
D Both are true
Explanation: By disjunctive syllogism, if A or B is true and A is false, B must be true.