Read the given statements and conclusions carefully. You have to take the given statements to be true even if they seem to be at variance from commonly known facts. You have to decide which conclusion/s logically follow/s from the given statements. Statements: Some telephones are curtains. All curtains are lamps. No lamps is books. Conclusions: (I) All lamps are telephones. (II) No books is lamps.

Correct — A.

Rule: a No statement reads the same in both directions; an All statement does not.

Conclusion (II). The third statement is No lamps is books. Turned round it says no books is lamps — the same fact in the other order, so (II) follows from that statement by itself.

Conclusion (I). Some telephones are curtains, and all curtains are lamps, so some telephones are lamps. Read the other way, that is Some lamps are telephones.

It stops there. Nothing rules out lamps that are neither curtains nor telephones, so All lamps are telephones is not licensed and (I) does not follow.

Conclusion (II) alone survives, which is option (a).

Why the others are wrong

• (b)
  Neither conclusion (I) nor (II) is follow — Rejects (II) as well. But No lamps is books and no books is lamps are the same statement written from the other end, so (II) is guaranteed by the third statement on its own.
• (c)
  Only conclusion (I) is follow — Exactly backwards. (I) claims every lamp is a telephone, which no combination of the statements licenses, while (II) is a straight reversal of a statement you were given.
• (d)
  Both conclusions (I) and (II) are follow — Accepts (I). Some telephones being curtains, and all curtains being lamps, yields only some lamps being telephones — an All conclusion cannot be built on a Some premise.

Two moves settle almost every syllogism of this shape: conversion, which reverses a single statement, and the chain, which joins two of them through a shared term.

Conversion is safe for No and for Some, and only partly safe for All: All A are B gives Some B are A, never All B are A. That single asymmetry is what conclusion (I) fails on.

A chain that starts from a Some premise can never end in an All conclusion. The most it can deliver is another Some, because only part of the first group was ever accounted for.

Key facts

• No A are B and No B are A are the same statement.
• Some A are B and Some B are A are the same statement.
• All A are B converts only into Some B are A.
• A chain built on a Some premise can only yield a Some conclusion.

Common traps

• Upgrading some lamps are telephones into all lamps are telephones.
• Rejecting (II) because it prints the two terms in the opposite order from the statement.
• Combining the first and third statements, which share no term and settle nothing together.

No directly related past PYQ was found.