Preeti starts from point A and drives 7 km towards South. From here, she takes a left turn and drives 9 km. She then takes a final left turn and drives 7 km to reach point B. How far should Preeti drive to reach point A from point B?

The correct option is 9 km.

Step-by-Step Explanation:

Let us trace Preeti's movement step-by-step starting from point A:

1. First Movement:
Preeti starts at point A and drives 7 km towards the South.

2. Second Movement (First Left Turn):
Facing South, a left turn directs her towards the East. She drives 9 km in this direction (East).

3. Third Movement (Second Left Turn):
Facing East, a left turn directs her towards the North. She drives 7 km in this direction (North) to reach point B.

4. Calculating the Distance between Point B and Point A:
The vertical displacement towards the South (7 km) is exactly cancelled by the vertical displacement back towards the North (7 km):

$7\text{km}-7\text{km}=0\text{km}$

Therefore, point B lies directly on the same horizontal line as point A, at a distance equal to her eastward drive:

$\text{Distance}=9\text{km}$

To reach point A directly from point B, Preeti needs to drive 9 km towards the West.