If I am asking a complex question, I would write it like this:
Do you have, by chance, three pennies on you?
Should I write a complex question that turns into a list without the comma?
Do you have, by chance:
- 3 pennies?
- 2 shillings?
or like this
Do you have, by chance,:
- 3 pennies?
- 2 shillings?