What does this rebus means ?

PROG WORKRESS

How many cubic feet of dirt are in a hole of one foot deep, three feet long, and two feet wide?

Take 9 from 6, 10 from 9, 50 from 40, and leave 6.

How Come ??

One night, a woman receives a call from the police. They tell her that her husband was murdered and that she should come to the crime scene as soon as possible. The woman drops the phone, shocked, and drives 20 minutes to the crime scene. As soon as she reaches the crime scene, the police arrest her and she is convicted of murder. How do the police know she committed the crime?

What is the end of everything?

In a chess board, the queen piece can move horizontally, vertically and diagonally freely. The picture represents the same.Can you place 8 queens on the board in a manner that none of the queens can attack each other?

What does this simple rebus mean?

How can you write nineteen in a manner that if we take out one, it becomes twenty?

I am not a bull but I have horns.
I am not an ass but I have a pack saddle.
Wherever I go, I leave silver behind me.

Who am I?

What does the below rebus riddle means?