Question

The FIRST and the LAST sentences of the paragraph are numbered 1 & 6. The others, labelled as P, Q, R and S, are given below. Arrange them to form the MOST LOGICALLY ORDERED paragraph.
1. The word “symmetry” is used here with a special meaning, and therefore needs to be defined.
P. For instance, if we look at a vase that is left-and-right symmetrical, then turn it $180^\circ$ around the vertical axis, it looks the same.
Q. When we have a picture symmetrical, one side is somehow the same as the other side.
R. When is a thing symmetrical — how can we define it?
S. Professor Hermann Weyl has given this definition of symmetry: a thing is symmetrical if one can subject it to a certain operation and it appears exactly the same after operation.
6. We shall adopt the definition of symmetry in Weyl’s more general form, and in that form we shall discuss symmetry of physical laws.
Which of the following combinations is the MOST LOGICALLY ORDERED?

• A. 1PQRS6
• B. 1QRSP6
• C. 1RQPS6
• D. 1RQPS6
• E. 1SPQR6

Hint:

In definition-building parajumbles, look for a flow of \textbf{Need} $\Rightarrow$ \textbf{Question} $\Rightarrow$ \textbf{Naive view} $\Rightarrow$ \textbf{Example/limitation} $\Rightarrow$ \textbf{Formal definition} $\Rightarrow$ \textbf{Adoption/Conclusion}. Discourse cues like “For instance” (P) and name-citing definitions (S) are strong anchors.

Answer 1

The Correct Option is D

Step 1: Fix the frame sentences.
Sentence 1 introduces a special meaning of “symmetry” and signals that a \textit{definition} is needed. Sentence 6 declares that we shall \textit{adopt Weyl’s definition}. Hence the middle must build from the need for a definition to Weyl’s formal statement.
Step 2: Ask the defining question.
R (“When is a thing symmetrical — how can we define it?”) naturally follows 1 because it explicitly raises the definitional problem that 1 sets up. Thus: 1 $\Rightarrow$ R.
Step 3: Begin with a naive/introductory idea.
Q gives the everyday view of symmetry (\textit{one side same as the other}). This directly attempts to answer R in a simple way. Therefore: R $\Rightarrow$ Q.
Step 4: Provide an illustrative counterexample that motivates generalization.
P starts with “For instance,” and shows a vase that remains the same after a $180^\circ$ rotation — a case of \textit{rotational} symmetry. This goes beyond the mirror/bilateral idea in Q and motivates a more general definition. Hence: Q $\Rightarrow$ P.
Step 5: State the general definition and close.
S gives Weyl’s formal definition in terms of an \textit{operation} under which the object appears unchanged, which neatly subsumes both bilateral and rotational symmetry. Finally, 6 adopts this definition, echoing “Weyl’s more general form.” Thus: P $\Rightarrow$ S $\Rightarrow$ 6.
Final order: \quad \boxed{1 \;\rightarrow\; R \;\rightarrow\; Q \;\rightarrow\; P \;\rightarrow\; S \;\rightarrow\; 6}
\[ \boxed{\text{Correct Answer: (D) } 1\,R\,Q\,P\,S\,6} \]