In the following question the first and the last parts of a short classroom incident are numbered 1 and 6. The remaining parts P, Q, R and S are jumbled. The passage shows how the teacher reacts when there is noise outside. Read the passage and choose the option that gives the correct order of P, Q, R and S.

Introduction / Context:
This paragraph rearrangement item describes a short classroom scene. The teacher first asks the boys to be quiet, and at the end we learn that a dog has entered the school premises. The middle parts describe a noise outside, the teacher's reaction, and the subsequent instruction to open books. You must put P, Q, R and S in an order that reflects normal classroom behaviour.

Given Data / Assumptions:

• Sentence 1 states that the teacher asked the boys to be quiet.
• Part Q says that suddenly there was some noise outside.
• Part S says that the teacher looked outside.
• Part R says that then he asked them to open their books.
• Part P says that the boys opened their books.
• Sentence 6 concludes that a dog had entered the school premises.

Concept / Approach:
The passage shows a simple sequence: instruction, disturbance, checking, returning to work, and compliance. The noise outside interrupts the quiet, the teacher checks the cause, then resumes teaching by asking students to open their books, and the students obey. The explanation of the noise (the dog) is postponed to the last sentence as a small twist.

Step-by-Step Solution:
Step 1: After the teacher asks the boys to be quiet, the next event mentioned is a disturbance. Part Q describes that suddenly there was some noise outside, which naturally follows sentence 1. Step 2: When noise is heard, the teacher would look to see what has happened. Part S captures this reaction: the teacher looked outside. Step 3: After checking the disturbance, the teacher returns to teaching. Part R says that he then asked the students to open their books. Step 4: Finally, part P reports the students' response: the boys opened their books. Sentence 6 then explains that the noise was caused by a dog entering the premises.

Verification / Alternative check:
Reading the sequence 1 Q S R P 6 yields a smooth classroom story: teacher asks for quiet, a noise occurs, teacher looks outside, then resumes the lesson by telling students to open their books, and they obey. At the end we find out that a dog was responsible for the noise. There is no contradiction in time or behaviour.

Why Other Options Are Wrong:
In PRSQ, the boys open their books before being told to do so, which is illogical. In RPQS, the teacher asks them to open their books immediately after asking for quiet, without any mention of the noise, which ignores the given sequence. In SQRP, the teacher looks outside before any noise is reported, which again breaks cause and effect.

Common Pitfalls:
One common error is to overlook temporal markers like “then” and “suddenly”. “Suddenly” in Q indicates the first unexpected event after the initial instruction, and “then” in R shows a later action. Pay close attention to such clues, and always make sure the actions of teacher and students respond logically to each other.

Final Answer:
The correct order of the parts is Q S R P, so the correct option is QSRP.