Canadian lotteries that don’t require the so-called skill-testing question (i.e. lottery tickets and casino games) are monopolized or heavily regulated by the various provincial governments. Anyone who wishes to run a private contest or raffle is obliged to distinguish their system by adding the question.
I don’t understand the justification, myself. I despise government regulations that force people to engage in meaningless rituals.
Time limits are not uncommon for contests where the winner will be contacted by the organizers. In those cases, the qualification is usually stated: “Contestants must answer a time-limited skill-testing question…”