Reasoning
Ability Syllogism Practice Questions – Set 13
Directions
(1 – 5): In each question some statements followed by some conclusions. You
have to take the given statements to be true even if they seem to be at variance
with commonly known facts and then decide which of the given conclusions
logically follows from the given statements.
1. Statements:
All books are copies.
All pens are books.
Some copies are pencils.
Conclusions:
I. All pens being
pencils is a possibility.
a) Neither I nor II follows
b) Only I follows
c) Either I or II follows
d) Both I and II follow
e) Only II follow
2. Statements:
Some roads are streets.
No street is highway.
All haighways are
crossings.
Conclusions:
I. Some roads are
not crossings.
II. No crossing is
highway.
a) Neither I nor II follows
b) Only I follows
c) Either I or II follows
d) Both I and II follow
e) Only II follows
3. Statements:
Some boys are girls.
Some girls are women.
All women are men.
Conclusions:
I. Some men are
girls.
II. All boys being
men is a possibility.
a) Neither I nor II follows
b) Only I follows
c) Either I or II follows
d) Both I and II follow
e) Only II follows
4. Statements:
All lions are tigers.
No tiger is dog.
All dogs are cats.
Conclusions:
I. All lions are
cats.
II. Some cats are
tigers.
a) Neither I nor II follows
b) Only I follows
c) Either I or II follows
d) Both I and II follow
e) Only II follows
5. Statements:
No red is a black.
All blacks are greens.
All greens are yellows.
Conclusions:
I. All blacks are
yellows.
II. At least some
yellows are greens.
a) Neither I nor II follows
b) Only I follows
c) Either I or II follows
d) Both I and II follow
e) Only II follows
Directions
(6 – 10): In the following questions three conclusions followed by four
statements in the options. You have to take the given conclusions to be
true even if they seem to be at variance from commonly known facts
and then decide which of the given statements in the options give the
given conclusions disregarding commonly known facts.
6. Conclusions:
Some men are not owls.
No frog is donkey.
Some foxes are donkeys.
a) All frogs are owls. No donkey is
owl. Some donkeys are men. All men are foxes.
b) Some frogs are not owls. Some
donkeys are owls. All donkeys are men. Some men are not foxes.
c) No frog is owl. Some donkeys are
owls. Some donkeys are not men. No man is fox.
d) Some frogs are owls. Some donkeys
are not owls. No donkey is man. Some men are not foxes.
e) None of these
7. Conclusions:
Some phones are pagers.
Some phones are keys.
All locks may be laptops.
a) Some locks are not pagers. All
pagers are laptops. No laptop is key. Some laptops are phones.
b) No lock is pager. Some pagers are
not laptop. All laptops are keys. No laptop is phone.
c) Some locks are pagers. Some pagers
are laptops. Some laptops are keys. All laptops are phones.
d) All locks are pagers. No pager is
a laptop. Some laptops are not keys. Some laptops are not phones.
e) None of these
8. Conclusions:
Some pens are erasers.
Some books may not be
pens.
No box may be basket.
a) All books are baskets. All baskets
are pens. All erasers are boxes. No box is pen.
b) All boxes are books. All books are
baskets. Some baskets are pens. Some eraser is basket.
c) All books are boxes. All boxes are
pens. Some pens are baskets. No basket is eraser.
d) All erasers are books. Some boxes
are erasers. All boxes are pens. Some baskets are books.
e) None of these
Directions
(9 – 10): In question, some statements are given, followed by two conclusions
I, II and III. You have to consider the statements to be true, even if they
seem to be at variance from commonly known facts. You have to decide which of
the given conclusions, if any, does not follow from the given statements.
9. Statement:
All rights are wrong.
All false are true.
Some right are false.
Conclusions:
I. Some false are wrong.
II. All true being wrong is a
possibility.
III. Some wrong can be true.
a) Only conclusion I
b) Onlly conclusion II
c) I and II
d) II and III
e) None of I, II and III
10. Statements:
Some glasses are not
goggles.
All glasses are gases.
No glass is a goose.
Conclusions:
I. Some gases are not
geese.
II. Some gases are not
goggles.
III. Some goggles are not
geese.
a) Only conclusion I
b) Only conclusion II
c) I and II
d) II and III
e) All I, II and III
Solutions:
1. B) Checking C1: All pens being pencils is a
possibility.
As there is no negative
statement, possibilities between classes do exist. Clearly, C1 follows.
Checking C2: All pens are not copies.
As there is no negative
statement, a negative definite conclusion is not possible. C2, hence, doesn't
follow.
2. A) Checking
C1: Some roads
are not crossings.
Here, S1 is I type, S2 is
E type, and the class 'crossings' is the predicate in S2 which is an A type
statement. When we move from S1 to S2, we get a conclusion in O type statement
and as we know O type doesn't make a definite conclusion applying deduction
method. No definite conclusion can be derived out of S1, S2 and S3 together.
C1, hence, doesn't follow.
Checking C2: No crossing is highway.
Converse of S3 = Some
crossings are highway. Clearly, C2 doesn't follow either.
3. D) Checking C1: Some men are girls.
Some girls are women +
All women are men = Some girls are men. Clearly, C1 follows.
Checking C2: All boys being men is a possibility.
Here, no negative
statement is given among the statements. Clearly, possibilities between classes
do exist. C2 follows as well.
4. A) Checking C1: All lions are cats.
The class 'lions' is in
Statement 1 and 'cats' is in Statement 3 and the link or middle term is
available in Statement 2 which is an E type statement. Clearly, using these we
can't have an A type conclusion. C1, clearly, doesn't follows.
Checking C2: Some cats are tigers.
Applying the same logic,
we can't get a positive conclusion using Statement 2 and Statement 3. C2, doesn't
follow either.
5. D) All
blacks are greens (A) + All greens are yellows (A) = A + A = All blacks are
yellows. Hence, conclusion I follows.
All greens are yellows –
converse – Some yellows are greens. Hence, conclusion II follows.
6. A) Option
A: All frogs are owls. No donkey is owl. Some donkeys are men. All men are
foxes.
C1: Some men are not
owls.
We can derive the above
conclusion using S2 and S3. “Donkeys” is the middle term here which is
distributed once in S2, and thus we can deduct the middle term to find the
conclusion – “Some men are not owls.”
C2: No frog is donkey.
We can derive the above conclusion
using S1 and S2. “Owls” is the middle term here which is distributed once in
S2, and thus we can deduct the middle term to find the conclusion – “No donkey
is owl.”
C3: Some foxes are
donkeys.
Let’s pick S3 and S4
here. The middle term is “men” which is being distributed in S4. We can
therefore deduct the middle term and the conclusion will be, “Some foxes are
donkeys.”
7. C) Option
C: Some locks are pagers. Some pagers are laptops. Some laptops are keys. All
laptops are phones.
C1: Some phones are pagers.
We can derive the above
conclusion using S2 and S4. “laptops” is the middle term here which is
distributed once in S4, and thus we can deduct the middle term to find the
conclusion – “Some phones are pagers.”
C2: Some phones are keys.
We can derive the above
conclusion using S3 and S4. “laptops” is the middle term here as well which is
distributed in S4, and thus we can deduct the middle term to reach the
conclusion – “Some phones are keys.”
C3: All locks may be laptops.
We can see that the
classes ‘locks’ and ‘laptops’ are present in S1 and S2 but the middle terms
“pagers” is not distributed even once in either of the statements which implies
possibilities between these two classes.
Hence, “All locks being
laptops is a possibility.” Or “All locks may be laptops.” follows.
8. D) Option
D: All erasers are books. Some boxes are erasers. All boxes are pens. Some
baskets are books.
C1: Some pens are erasers.
We can deduce a
relationship between the classes ‘Pens’ and ‘Erasers’ using S2 and S3. The
middle term “boxes” is distributed once in S3 and hence we can deduct the
middle term to reach the conclusion – “Some pens are erasers.”
C2: Some books may not be pens.
We have already deduced
the conclusion above – “Some pens are erasers” using this and S1 we can deduce
a relationship between the classes ‘pens’ and ‘erasers’. The middle term here
is “erasers” which is distributed in S1. We can hence deduct the middle term
“erasers” and the conclusion will be, “Some books are pens.” Which further
implies the possibility that if some books are pens, some (other) books may or
may not be pens. Hence, C2 gets validated here.
C3: No box may be basket.
In the statements we can
observe that there from S1 and S2 we can deduce the conclusion “Some boxes are
books.” Now, using this and S4 we can deduce a relationship between the classes
‘box’ and ‘basket’ but as the middle term ‘books’ is not distributed even once
in either of the statements, possibilities between these two classes exist.
Hence, C3 follows as well.
9. E) From statement III and I:
Some rights are false (I)
– conversion – Some false are right (I) + All rights are wrong (A) = I + A = I
= Some false are wrong. Hence, conclusion I
follows.
Since there is no
negative statement, conclusion II and III also follow.
So, there is no
conclusion that doesn't follow.
10. A) From statement II and III:
All glasses are gases –
conversion – Some gases are glasses (I) + No glass is a goose (E) = I + E = O =
'Some gases are not geese' which is given as conclusion I. Hence conclusion I
follows.
From statement II and I:
Some gases are glasses
(I) (which is converse of S2) + Some
glasses are not goggles (O) = I + O = No conclusion. Hence conclusion II does
not follow.
From statement I and III:
Some glasses are not
goggles (O) + No glass is a goose (E) = No conclusion. Hence conclusion II does
not follow either.
