I would use a 1D array. Each value containing the ID of the question.
Setting up the array:
On start of layout
-array for each element X
-set X value at array.CurX to array.CurX
Choosing a random question:
if question=0 ... array delete index 0 on X axis / set text "Question one?"
if question=1 ... array delete index 1 on X axis / set text "Question two?"
if question=2 ... array delete index 2 on X axis / set text "Question three?"
if question=3 ... array delete index 2 on X axis / set text "Question four?"
And so on. You delete each question out of the array because you don't want it to appear more than once.