Answer:
3 o'clock (5, 0)
6 o'clock (0, -5)
9 o'clock (-5, 0)
12 o'clock (0, 5)
Explanation:
Given that diameter of clock = 10 units
We know that:

Radius = 5 units
The length of face will be equal to radius of clock i.e.
Length of face = 5 units
For the question, we need to visualize the clock time 3 o'clock, 6 o'clock, 9 o'clock and 12 o'clock on the coordinate xy axis.
Please refer to the attached graph to have a better understanding.
In every 3 hours the face will move
i.e. one quadrant as per the location of clock faces.
At 3 o'clock the face will be on the positive x axis.
So coordinate (5, 0)
At 6 o'clock the face will be on the negative y axis.
So coordinate (0, -5)
At 9 o'clock the face will be on the negative x axis.
So coordinate (-5, 0)
At 12 o'clock the face will be on the positive y axis.
So coordinate (0, 5)
So, the answer is:
3 o'clock (5, 0)
6 o'clock (0, -5)
9 o'clock (-5, 0)
12 o'clock (0, 5)