Vedadots
Q3738/80Q39
Q38·CSAT · Prelims 2022

Syllogism evaluation with basic Venn diagram propositions

ReasoningSyllogismFactual singleEasy

Question

Two Statements followed by four Conclusions are given below. You have to take the Statements to be true even if they seem to be at variance from the commonly known facts. Read all the Conclusions and then decide which of the given Conclusions logically follows/follow from the Statements, disregarding the commonly known facts: Statement-1: All pens are books. Statement-2: No chair is a pen. Conclusion-I: All chairs are books. Conclusion-II: Some chairs are pens. Conclusion-III: All books are chairs. Conclusion-IV: No chair is a book.

Options

a

Only Conclusion-I

b

Only Conclusion-II

c

Both Conclusion-III and Conclusion-IV

d

None of the Conclusions follows

Answer

Explanation

Draw the Venn diagram based on the premises:

1P \subset B: The entire circle for Pens is inside the circle for Books.
2C \cap P = \emptyset: The circle for Chairs is completely separated from the circle for Pens.

Now evaluate the boundary limits for Chairs (C): Because Chairs cannot touch Pens, the Chair circle must stay outside the Pen circle. However, since the Pen circle is inside the Book circle, the Chair circle can legally exist completely outside Books, partially overlapping Books, or entirely inside the non-Pen section of Books.

Check Conclusions:

I: All chairs are books. (False, they could be completely outside Books).
II: Some chairs are pens. (False, explicitly violates Statement 2).
III: All books are chairs. (False, Books contain Pens, which cannot be Chairs).
IV: No chair is a book. (False, Chairs could partially overlap the Book circle).

Since none of these relationships are guaranteed to be true in all possible diagrams, none logically follow.

In negative syllogisms ("No A is B"), if B is a subset of C, A is barred from B but retains complete freedom to overlap or avoid the outer shell of C.

Answer: (d).

Question details

Year

2022

Paper

CSAT

Question

Q38

Section

Logical & Analytical Reasoning

Sub-topic

Syllogism

Type

Factual single

Difficulty

Easy

Source hint

All pens are books. No chair is a pen.

Same sub-topic — other years

Syllogism has appeared in multiple CSAT papers:

See all questions on Syllogism

Browse every tagged question across all years

Explore →