S1: Once upon a time a dog lived on the bank of a river. P: An elephant saw…

Sentence-rearrangement (para-jumble) questions fix an opening and closing sentence and ask you to order the movable fragments in between. The order is fixed by tracing the narrative's cause-and-effect chain together with each fragment's references: an event must appear before its consequence, and a new character introduced with a full noun phrase (such as "an elephant") must be placed in the scene before anything is said about what it does.

1. S1 sets the scene — the dog lives on the river bank; nothing has happened to it yet.

2. R must follow directly: "One day he suddenly slipped into the water" is the inciting incident, the first thing that can happen to the dog once the scene is set.

3. Q follows R: "All its efforts went in vain" describes the direct consequence of the slip — the dog's own failed struggle to get out. An effort can only "go in vain" once there is a mishap to struggle against, so Q needs R immediately before it.

4. S comes next: "An elephant was passing by the river not far from the spot" introduces a brand-new character (the elephant, named with the full phrase "an elephant" for the first time) arriving at the scene while the dog is already struggling.

5. P follows S: "An elephant saw the dog struggling in water" is the elephant's action of noticing the dog — this can only happen once the elephant has already been placed at the spot (S), so P must come right after S.

6. S6 closes: "He was touched" — the pronoun "he" now refers back to the elephant just introduced in S and P, confirming P is the last movable fragment before S6.

This produces the order R-Q-S-P.

Checking the other arrangements confirms this:

• QRPS opens with Q ("All its efforts went in vain"), describing a failed struggle before the dog has even had any mishap to struggle against — an effort cannot go in vain before the incident that causes it.

• SRPQ places Q last, so the sequence ends on the dog's failed efforts rather than on the elephant — but the closing line's pronoun "he" needs the elephant (introduced in S, noticing in P) to be the most recently mentioned character, which this ordering breaks.

• PQRS opens with P, having the elephant see the dog struggling before the elephant has even been placed at the river (S) or the dog has slipped in (R) — the observation comes before both its cause and its observer's arrival.

Only R-Q-S-P keeps every fragment placed after the event or character it depends on, confirming it as the correct sequence.