Logical Deduction Questions and Answers (2023)

Logical deduction is a vital skill in critical thinking and problem-solving. This skill is helpful in many areas of life, such as making choices and solving tricky puzzles. In simple terms, logical deduction involves examining evidence, identifying patterns, and drawing logical conclusions.

It requires thinking clearly, avoiding mistakes, and arriving at correct and dependable conclusions. Whether you’re unraveling a mystery, tackling mathematical problems, or making important decisions at work, logical reasoning is a highly valuable skill to have.

Logical Deduction Questions with Answers

1. Statements: All dogs are mammals. Some mammals are cats.

Conclusions:

• All dogs are cats.
• Some cats are dogs.

A. Only conclusion I follows

B. Only conclusion II follows

C. Either I or II follows

D. Neither I nor II follows

E. Both I and II follow

Answer: Neither I nor II follows

Explanation: In this case, the premises establish that dogs are mammals, but they do not establish a direct relationship between dogs and cats. Therefore, neither of the conclusions can be logically deduced from the given premises.

2: Statements: All students who study regularly pass exams. John studies regularly.

Conclusions:

• John is a student.
• John will pass exams.

A. Only conclusion I follows

B. Only conclusion II follows

C. Either I or II follows

D. Neither I nor II follows

E. Both I and II follow

Answer: Both I and II follow

Explanation: The first conclusion logically follows from the given premises because if all students who study regularly pass exams, and John studies regularly, then John must be a student. The second conclusion also follows logically because, according to the premises, if John is a student who studies regularly, he will pass exams.

3. Statements: No reptiles are mammals. Some mammals are primates.

Conclusions:

• Some reptiles are not primates.
• Some mammals are reptiles.

Answer: None

Explanation: The first conclusion cannot be logically deduced because the premises state that no reptiles are mammals, but they do not provide information about the relationship between reptiles and primates. The second conclusion cannot be deduced either because the premises establish that some mammals are primates, but they do not provide information about reptiles.

4. Statements: All politicians are public speakers. Some public speakers are lawyers.

Conclusions:

• All politicians are lawyers.
• Some lawyers are politicians.

Answer: None

Explanation: The first conclusion cannot be logically deduced because the premises establish that all politicians are public speakers, but they do not provide information about lawyers. The second conclusion cannot be deduced either because the premises state that some public speakers are lawyers, but they do not establish a relationship between lawyers and politicians.

5. Statements: If it rains, the ground gets wet. The ground is wet.

Conclusions:

• It rained.
• If the ground is wet, it rained.

Answer:

• It rained.
• If the ground is wet, it rained.

Explanation: The first conclusion logically follows because if the ground is wet, it implies that it rained (based on the first premise). The second conclusion also follows because it restates the conditional relationship established in the first premise.

6. Statements: All birds can fly. Penguins are birds.

Conclusions:

• Penguins can fly.
• Some birds can swim.

Answer:

Penguins can fly.

Explanation: The first conclusion cannot be logically deduced because the premises state that all birds can fly, but penguins are an exception to this rule as they cannot fly. The second conclusion cannot be deduced either because the premises do not provide information about swimming.

7. Statements: If it is daytime, it is light outside. It is light outside.

Conclusions:

• It is daytime.
• If it is light outside, it is daytime.

Answer:

• It is daytime.
• If it is light outside, it is daytime.

Explanation: Both conclusions logically follow from the given premises. The first conclusion follows because if it is light outside, it implies that it is daytime (based on the first premise). The second conclusion restates the conditional relationship established in the first premise.

8. Statements: All squares are rectangles. Some rectangles are not circles.

Conclusions:

• Some circles are squares.
• No squares are circles.

Answer:

Some circles are squares.

Explanation: The first conclusion logically follows because if all squares are rectangles, then some rectangles can be squares. The second conclusion cannot be deduced because it contradicts the information provided in the premises. The premises do not establish that no squares are circles.

9. Statements: All doctors are educated. Some educated people are engineers.

Conclusions:

• Some engineers are doctors.
• All educated people are doctors.

Answer: None

Explanation: The first conclusion cannot be logically deduced because the premises establish that some educated people are engineers, but they do not provide information about doctors. The second conclusion cannot be deduced either because the premises state that all doctors are educated, but they do not establish that all educated people are doctors.

10. Statements: If it is cold, people wear jackets. People are wearing jackets.

Conclusions:

• It is cold.
• If people are wearing jackets, it is cold.

Answer:

• It is cold.
• If people are wearing jackets, it is cold.

Explanation: Both conclusions logically follow from the given premises. The first conclusion follows because if people are wearing jackets, it implies that it is cold (based on the first premise). The second conclusion restates the conditional relationship established in the first premise.

Conclusion

Logical deduction questions and answers can be a helpful tool for improving your logical reasoning skills. By practicing with these types of questions, you can learn how to identify the logical relationships between different statements and to draw valid conclusions.