Who is sitting between Rachel and Sandra?

Concept

In a single-row (linear) seating arrangement, once the fixed left-to-right order of everyone in the row is known, the person sitting “between” two named people is simply whoever occupies the one seat that lies strictly between their two positions in that order.

Application

1. The five people are seated left to right in this order: Rachel, Carla, Sandra, Maria, Sara.

2. Locate the two names from the question in this order: Rachel is 1st and Sandra is 3rd.

3. The only seat lying strictly between position 1 and position 3 is position 2, which is occupied by Carla.

Cross-check

Checking neighbours confirms this: moving right from Rachel, the very next person is Carla, and the next person after Carla is Sandra — so Carla alone fills the gap between them, with no one else in between.

∴ Carla is sitting between Rachel and Sandra.