First, read all your questions into a
List.[
^]
Next, use the random number generator to generate a random number between 0 and n, where n is the count of the list items minus 1.
Display that question, and remove it from the list if you don't want it to show up again. Repeat at the second step.
If you gave code or a database schema, I could expand on this with code as well, but since you didn't give anything to work with, all I can give you is the process.