“Deduction is the art of deriving from accepted premises a conclusion which

is logically certain.”
— Aristotle

“Induction, like analogy, and indeed like every method which cannot give us
demonstrable certainty, only gives us probability.”
— John Stuart Mill

Instructions:

Read each argument carefully. Decide if it is Deductive (where the conclusion is

necessarily true if the premises are true) or Inductive (where the conclusion is
probable based on the premises). Write D for Deductive or I for Inductive.

1. All birds have feathers. A sparrow is a bird. Therefore, a sparrow has

feathers.
Answer: ______
D

2. Every time it rains, the streets get wet. It is raining now. So, the streets
will be wet.
Answer: ______
I

3. If it’s summer, then the days are longer than the nights. Today is a
summer day. So, the day will be longer than the night.
Answer: ______
D

4. All fruits contain seeds. A banana contains seeds. Therefore, a banana

is a fruit.
Answer: ______
D

5. In most cases, people who get a college degree earn more than those
who don’t. She has a degree. She will probably earn more than those
without a degree.
Answer: ______
I

6. If it snows, then the temperature is below freezing. It is below freezing,

so it must be snowing.
Answer: ______
I

7. 90% of the students in the class passed the exam. María is in the class,
so she likely passed the exam.
Answer: ______
8. All mammals breathe air. Dolphins are mammals. Therefore, dolphins
breathe air.
Answer: ______
D

9. Usually, when people work out regularly, they feel more energetic.
Since Alex works out regularly, he likely feels more energetic.
Answer: ______
I

10. The sun rises in the east every day. Tomorrow, the sun will rise in the
east.
Answer: ______
I

11. Every swan that has been observed is white. Therefore, all swans must
be white.
Answer: ______
I

12. If Juan is taller than Pedro, and Pedro is taller than Luis, then Juan is
taller than Luis.
Answer: ______
D

13. The Earth has had life for billions of years, so life likely exists on other
planets too.
Answer: ______
I

14. No fish can breathe air. A shark is a fish. Therefore, a shark cannot
breathe air.
Answer: ______
D

15. In most cases, people who live in the city walk more than those in the
countryside. John lives in the city, so he likely walks more.
Answer: ______
I

16. If a figure is a triangle, it has three sides. This shape is a triangle.

Therefore, it has three sides.
Answer: ______
D

17. It’s been sunny every Friday this month, so it’ll probably be sunny next
Friday as well.
Answer: ______
I

18. If someone is a bachelor, then they are unmarried. Lucas is a bachelor.

Therefore, Lucas is unmarried.
Answer: ______
D

19. Most dogs bark when they see a stranger. Since that dog is barking, it’s
probably because it sees a stranger.
Answer: ______
I
20. All squares have four equal sides. This shape is a square. Therefore, it
has four equal sides.
Answer: ______
D

21. Each time I eat at that restaurant, I get food poisoning. I’m likely to get
sick if I eat there again.
I
Answer: ______

22. If the glass is dropped, it will fall to the ground. The glass was dropped.
Therefore, it fell to the ground.
Answer: ______
D

23. 80% of the students who study pass the exam. She studied, so she’s
likely to pass.
Answer: ______
I

24. If two angles add up to 180 degrees, then they are supplementary. Angle
A and Angle B add up to 180 degrees. So, they are supplementary.
Answer: ______
D

25. Most people who live near water enjoy swimming. Max lives near the
lake, so he likely enjoys swimming.
Answer: ______
I

26. All humans are mortal. Socrates is human. Therefore, Socrates is

mortal.
Answer: ______
D

27. Every time Sarah goes hiking, she sees a fox. Therefore, she will see a
fox if she goes hiking tomorrow.
Answer: ______
I

28. The definition of a square is a figure with four equal sides and angles.
This figure has four equal sides and angles. So, it is a square.
Answer: ______
D

29. When it snows, it gets very cold. It is snowing, so it must be very cold.
Answer: ______
I

30. The majority of teenagers use social media daily. Since Maria is a
teenager, she likely uses social media daily.
Answer: ______
I
Reflection:

Write a brief paragraph explaining the key difference between deductive and
inductive reasoning, using examples from the exercises above.

The key difference between deductive and inductive reasoning is that, each one of them has a
different approach on stating or confirming a conclusion due to the premises that are
presented expectating and asumming each of the premises, can be one or two are fully true
and have a connection within the reason. For example, in Exercise 28, "The definition of a
square is a figure with four equal sides and angles. This figure has four equal sides and
angles. So, it is a square," the conclusion is necessarily true if the premises are accurate. . For
instance, in Exercise 27, "Every time Sarah goes hiking, she sees a fox. Therefore, she will
see a fox if she goes hiking tomorrow," the conclusion is likely based on past experiences, but
it is not guaranteed.