Answer:
The period of the pendulum is 
Explanation:
The diagram illustrating this setup is shown on the first uploaded image
From the question we are told that
The length of the rod is 
The diameter of the ring is 
The distance of the hole from the one end 
From the diagram we see that point A is the center of the brass ring
So the length from the axis of rotation is mathematically evaluated as

Now the period of the pendulum is mathematically represented as


