Question Database: Critical Thinking
Generalisations
Whenever it rains or snows, the match is cancelled.
Which of the following situations are counter-examples to the generalisation?
I. On Monday the match was cancelled, but it wasn't raining.
II. On Tuesday it was snowing and the match was cancelled.
III. On Wednesday, there was rain but no snow and the match was cancelled.
IV. On Thursday there was snow, but no rain and the match was not cancelled.
A. IV only
B. I and II
C. I and IV
D. III only
Answer: A
Topic:
Generalisations. Counter-examples.
Course Level:
First year, critical thinking.
Notes:
2006: Mostly A, some C
All Norwegian parrots are blue.
Which of the following birds are counter-examples to the generalisation?
Bird I. This bird is a parrot, but is not blue.
Bird II. This parrot is not blue, but is Norwegian.
Bird III. This bird is blue parrot, but not Norwegian.
Bird IV. This Norwegian bird is a red parrot.
A. I and II
B. II only
C. II and III
D. II and IV
Answer: D
Topic:
Generalisations. Counter-examples.
Course Level:
First year, critical thinking.
Notes:
2006: Mostly D, some C
Rule: If a passenger wishes to enter the country, then he or she must have had an inoculation against cholera.
You are checking passenger immigration cards at the airport. One side of each card shows whether the passenger is entering or in transit. On the other side of each card is a list of all the inoculations the passenger has had.
Which cards MUST you turn over to enforce the rule?
1. Entering
2. In transit
3. Cholera, Hepatitis
4. Typhoid
A. 1 only
B. 1 and 3
C. 2 and 4
D. 1 and 4
Answer: D
Topic:
Generalisations. Counter-examples.
Course Level:
First year, critical thinking.
Notes:
This is a version of the four-card problem. Most people find these 'realistic' examples much easier than abstarct problems.