Logical Deduction - Solved Questions and Answers
Logical deduction is the process of reasoning from one or more premises to reach a logically certain conclusion.
Logical Deduction questions and answers are provided below for you to learn and practice.
Question 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 followsExplanation:
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.
Question 2:
Statements:
All roses are flowers.
Some flowers are tulips.
Conclusions:
All roses are tulips.
Some tulips are roses.
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 followsExplanation:
The premises link roses to flowers and flowers to tulips, but they do not create a direct connection between roses and tulips. Without additional information, neither conclusion can be confirmed.
Question 3:
Statements:
No reptiles are mammals.
Some mammals are primates.
Conclusions:
Some reptiles are not primates.
Some mammals are reptiles.
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 followsExplanation:
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.
Question 4:
Statements:
All politicians are public speakers.
Some public speakers are lawyers.
Conclusions:
All politicians are lawyers.
Some lawyers are politicians.
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 followsExplanation:
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.
Question 5:
Statements:
If it rains, the ground gets wet.
The ground is wet.
Conclusions:
It rained.
If the ground is wet, it rained.
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 followExplanation:
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.
Question 6:
Statements:
All birds can fly.
Penguins are birds.
Conclusions:
Penguins can fly.
Some birds can swim.
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: Only conclusion I followsExplanation:
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.
Question 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.
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 followExplanation: 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.
Question 8:
Statements:
All squares are rectangles.
Some rectangles are not circles.
Conclusions:
Some circles are squares.
No squares are circles.
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 followsExplanation:
The premises link squares to rectangles and establish that some rectangles aren't circles, but they do not create any direct connection between squares and circles. Without information about whether any squares or other rectangles might be circles, neither conclusion can be confirmed.
Question 9:
Statements:
All doctors are educated.
Some educated people are engineers.
Conclusions:
Some engineers are doctors.
All educated people are doctors.
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 followsExplanation:
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.
Question 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.
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 followExplanation:
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.
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