In accordance to your demand we could use multiple question in a day for different users, but in this scenario the competition would not be an actual one as because a single puzzle may be easy for some individuals to solve but may be tough for the remaining others. According to our team this (easy/tough) puzzle distribution systems would not result in selecting the actual Genuine winner.
One more point I would like to make here is the new 30min Addition Rule. If any one logins after 11:30am then they could calculate their actual time by deducting these 30 min and then they could judge their actual position as if he logins at 11:00 AM sharp.
But if the individuals need to come up in top position then they have to login at 11:00 sharp.
Because in Today’s world the Time actually Counts !!!
Thanks for the suggestion. I am also looking for the best solution for this. The draw back of this concept is that someone will create 2 accounts and will see the puzzle from 1st and give us the answer from second account.