How Would You Organize a 15-Minute Talk Show with On-the-Spot Topics?

Hello All,

I am on the verge of organizing a talk show for 15 minutes. The topics will be given on the spot to the speakers, and they will have 30 seconds to prepare before they speak.

I would appreciate your suggestions on this matter. I have the startup and some topics in mind:

1. What if zero was not invented?
2. What if supply is more and demand is less?
3. What would happen in business if advertisements were banned?

I would like to receive your inputs.

Thanks,
Harish