Hi there,
I'd be advised to either do one introduction and conclusion overall or do one introduction and conclusion for each question. However I always preferred to do one introduction and conclusion overall. Yes, I would also include an introduction and conclusion for each question but it would be no more than a sentence due to the limited word count.
If you want to do one introduction and conclusion overall, just make sure you are addressing each of the questions clearly in the introduction and conclusion. You could address each question in different paragraphs within the introduction and conclusion.
I hope this helps (and makes sense too 🙂).
Best wishes,
Narusha
Coventry University Student Ambassador