Open Office Impress Gurus how-to query

Next week, I’ll be conducting an English speaking test for the 8th graders at my school. The student will choose three questions at random and, for each question, has only 30 seconds to answer.

I have an Impress presentation prepared where the first slide has numbered buttons for the question numbers. When I click on the question button, the presentation will jump to the slide with that question. I also have a button on each question slide to click and take me back to the question selection screen.

What I would like is to have a countdown timer, preferably an analog clock, that starts at 30 seconds and when it reaches zero, will have the presentation jump back to the question selection screen.

So, is this possible or am I doomed to use an actual stopwatch?

What also would be great is if I could add a random number generator on the selection screen. The numbers would not change until ordered to. I’m not all that worried about this one, though.

Thanks in advance!