Syllogism

Syllogism is a part of logical reasoning, especially analytical reasoning. It consists of some statements, and candidates need to derive conclusions from the given statements. The statements and conclusions may seem to be illogical, but while solving questions related to syllogism in reasoning, candidates must assume the given statements to be 100% true.

Syllogism reasoning questions check the basic aptitude and ability of a candidate to derive inferences from given statements using step-by-step methods of solving problems. Let us now understand the various types of Syllogism from below.

Basics of Syllogistic Reasoning

“A class is defined to be the collection of all objects that have some characteristics in common”. Classes can be related to each other in many ways. If every member of one class is also a member of a second class, then the first class is said to be included or contained in the second. If some but perhaps not all members of one class are also member of another, then the first class may be said to be contained partially in the second class. Of course, there are pairs of classes having no members in common, such as the class of all triangles and the class of all circles.

Now let us take 4 statements

All persons are kind.
No person is kind.
Some persons are kind
Some persons are not kind.

The first statement is about two classes and clearly defines that the first class is included in the second.
The second statement says that the first class is wholly excluded from the second.
The third statement says that at least one member of class 1 is also a member of class 2.
The fourth similarly implies that at least one person is not kind.
Note: it is important to understand the above four statements completely before proceeding further.

Types of Syllogism in Reasoning

As now we know what is Syllogism, let us see the various types of syllogism questions in the reasoning section below.

1. Basic Syllogism

In these type of syllogism reasoning questions, the conclusions must be 100% true. Conclusions which are 99% true will be considered as False.

2. Either – or Case

In these type of syllogism reasoning questions, when the conclusions are not 100% true but the two given conclusions are 50% true then the either-or case will be formed.

3. Coded Syllogism

In these types of syllogism reasoning questions, statements and conclusions are given in coded form. Candidates need to decode the statements and conclusions to find the answer.

4. Sequential Syllogism

In these type of syllogism reasoning questions, statements are given followed by the options. Candidates need to choose the set in which the third statement can be logically deduced from the first two statements.

How to Solve Syllogism Questions in Reasoning– Tips and Tricks

Candidates can find various tips and syllogism logical reasoning tricks from below for solving the questions in this section.

Tip # 1: If a definite conclusion is false in any of the possible diagrams, then the definite conclusion is considered to be false.

Tip # 2: If all statements are positive, then all negative conclusions will be false in definite cases and vice versa.

Tip # 3: Subject and Predicate can interchange for the complementary pair “Some + No”

Tip # 4: In a syllogism reasoning problem, if two conclusions have the same subject & predicate and consist of a complementary pair but only one of the conclusions is true, then it will not form an either-or case. Do not consider “Some + Some” as a complementary pair for Either or case.

Tip # 5: If a possible conclusion is true in any one of the possible diagrams, then the possibility is considered to be true.

Tip # 6: “Only a few” means both conclusions are definitely true.

Therefore, the conclusion, some A are B and some A are not B will be definitely true.

Tip # 7: In a syllogism reasoning problem, complementary pairs for Either or case are, “Some + N” and “All + Some not”

Tip # 8: Both conclusions should consist of one of the above complementary pairs. Subject and Predicate of the two conclusions should be the same and they cannot interchange. The answer of both the conclusions should be can’t be said.

Tip # 9: Candidates need to keep the following things in mind while solving the syllogism based questions.

Statement	Definite Conclusion	Possible Conclusion
All A are B	All A are B Some A are B .Some B are A	All B are A Some B are not A
Some A are B	Some A are B Some B are A	All A are B All B are ASome A are not B Some B are not A
Some A are not B	Some A are not B	Some A are B No A is B No B is ASome B are not AAll B are A
No A is B	No A is BNo B is A	No possibility is true

Practice Questions:

Q1. Consider the following three statements:
1. Only students can participate in the race.
2. Some participants in the race are girls.
3. All girl participants in the race are invited for coaching.
Which one of the following conclusions can be drawn from the above statements?
(a) All participants in the race are invited for coaching.
(b) All students are invited for coaching.
(c) All participants in the race are students.
(d) None of the statements (a), (b) and (c) given above is correct.

Q2. Consider the following statements:
1. All machines consume energy
2. Electricity provides energy
3. Electrically operated machines are cheap to maintain
4. Electrically operated machines do not cause pollution.
Which one of the following inferences can be drawn from the above statements?
a) All machines are run by electric energy.
b) There is no form of energy other than electricity
c) Most machines are operated on electric energy.
d) Electrically operated machines are preferable to use.

Q3. Examine the following statements:
1. None but the rich ran afford air-travel.
2. Some of those who travel by air become sick
3. Some of those who become sick require treatment
Which one of the following conclusions can be drawn from the above statements?
a) All the rich persons travel by air.
b) Those who travel by air become sick
c) All the rich persons become sick.
d) All those who travel by air are rich

Q4. Examine the following statements:
1) I watch TV only if I am bored
2) I am never bored when I have my brother’s company.
3) Whenever I go to the theatre I take my brother along.
Which one of the following conclusions is valid in the context of the above statements?
a) If I am bored I watch TV
b) If I am bored, I seek my brother’s company.
c) If I am not with my brother, than i’ll watch TV.
d) If I am not bored I do not watch TV.

Q5. Examine the following statements:
1. None but students are the members of the club.
2. Some members of the club are married.
3. All married persons are invited for dance.
Which one of the conclusions can be drawn from the above statements?
a) All students are invited for dance
b) All married students are invited for dance
c) All members of the club are married person
d) None of the above conclusions can be drawn

Q6. Consider the following statements:
1. All X-brand cars parked here are white.
2. Some of them have radial tyres
3. All X-brand cars manufactured after 1986 have radial tyres are parked here.
4. All cars are not X-brand.
Which one of the following conclusions can be drawn from the above statements?
a) Only white cars are parked here.
b) Some white X-brand cars with radial tyres are parked here.
c) Cars other than X-brand cannot have radial tyres.
d) Most of the X-brand cars are manufactured before 1986.

Q7. Examine the following statements:
1. Either A & B are of same age or A is older than B
2. Either C & D are of same age or D is older than C
3. B is older than C
Which of the following conclusions can be drawn from the above statements?
a. A is older than B
b. B and D are of the same age
c. D is older than C
d. A is older than C

Q8. Examine the following statements:
1. Only those who have a pair of binoculars can become the member of the birdwatcher’s club.
2. Some members of the birdwatcher’s club have cameras.
3. Those members who have cameras can take part in photo-contests.
Which of the following conclusions can be drawn from the above statements?
a) All those who have a pair of binoculars are members of the birdwatcher’s club.
b) All members of the birdwatcher’s club have a pair of binoculars.
c) All those who take part in photo-contests are members of the birdwatcher’s club.
d) No conclusion can be drawn.

Q9. During the summer vacation Ankit went to a summer camp where he took part in hiking, swimming and boating. This summer, he is looking forward to a music camp where he hopes to sing, dance and learn to play the guitar.
Based on the above information four conclusions as given below, have been made. Which one of these logically follows from the information given above?
a) Ankit’s parents want him to play guitar.
b) Ankit prefers music to outdoor activities.
c) Ankit goes to some type of camp every summer.
d) Ankit likes to sing and dance.

Q10. Statements: Some actors are singers. All the singers are dancers.
Conclusions:

Some actors are dancers.
No singer is actor.
A. Only (1) conclusion follows
B. Only (2) conclusion follows
C. Either (1) or (2) follows
D. Neither (1) nor (2) follows

Q11. Statements: All the harmoniums are instruments. All the instruments are flutes.
Conclusions:

All the flutes are instruments.
All the harmoniums are flutes.
A. Only (1) conclusion follows
B. Only (2) conclusion follows
C. Either (1) or (2) follows
D. Neither (1) nor (2) follows

Q12. Statements:

Some mangoes are yellow.
Some tixo are mangoes.
Conclusions:

Some mangoes are green.
Tixo is yellow.

A. Only (1) conclusion follows
B. Only (2) conclusion follows
C. Either (1) or (2) follows
D. Neither (1) nor (2) follows

Q13. Statements:

Some ants are parrots.
All the parrots are apples.
Conclusions:
All the apples are parrots.
Some ants are apples.
A. Only (1) conclusion follows
B. Only (2) conclusion follows
C. Either (1) or (2) follows
D. Neither (1) nor (2) follows

Q14. Statements: