James walks $40$ metres in the West direction, turns left and walks another $30$ metres. How far and in which direction is he from his starting point?

Let the starting point be $(0,0)$.
1. James walks $40\text{ m}$ West $\to$ new coordinate is $(-40,0)$.
2. He turns left (facing West, turning left means heading South) and walks $30\text{ m}$ $\to$ final coordinate is $(-40,-30)$.

Distance from starting point:
Using the Pythagorean theorem:

$$\text{Distance}=\sqrt{(-40{)}^2+(-30{)}^2}=\sqrt{1600+900}=\sqrt{2500}=50\text{ metres}$$

Direction from starting point:
Since the final coordinate $(-40,-30)$ lies in the negative X and negative Y directions relative to the origin, he is in the South-West direction.