In mid-January 2021, I posted the official rules for my Math mini-contest for active D.Buzz members which was intended to run for 7 days.

That contest then ran for 10 days, due to no one being able to answer the last day (Day 7) problem correctly that prompted an extension of that mini-contest. Now, I shall host a Math mini-contest for the entire month of February 2021. Here are the actual official rules for the contest! 😎

Just leave your answer as a comment for the Math problem you are trying to answer within 24 hours after it was posted. No solutions or explanations required!

Official rules

1. Only active D.Buzz members can win prizes. To be considered active on D.Buzz, a Hive user must have posted on the D.Buzz community or the D.Buzz website at least 7 days for the past 14 days.
2. I will post a Math problem every 24 hours starting at 03:00 P.M. (GMT+8) on February 1, 2021 (Monday) until February 28, 2021 (Sunday). I will use #PeakD's scheduled posts feature to ensure that the problem gets published on time. If nobody submitted a correct and valid answer, see #5. I will try to check if #PeakD actually published my scheduled post sometime after the scheduled time if it actually got posted, but I will not be responsible for any participant waiting if the post scheduling function encounters a technical issue.
3. Any interested and qualified participant must comment their answer on my post containing the Math problem, or below their answer which they wanted to be changed. Posting the answer anywhere else will make it invalid. If a participant wants to change their answer, see #6.
4. Participants are allowed to ask for help in solving the Math problem.
5. This mini-contest for February 2021 will run for exactly 28 days. Whenever nobody submitted a valid and correct answer for a day, the prize of 1 HIVE for the day shall be distributed to the previous winners in proportion to how many times they won for the month. For example, if nobody correctly answered the problem for February N, the day's prize of 1 HIVE shall be split into (N-1-X) equal parts corresponding to the previous N days (February 1 to 6), where X refers to the number of days from the previous days when nobody answered correctly. Each part of 1 HIVE shall be distributed to the previous winners depending on how many times they won for the month.
6. The winner for the day shall be the first user who submitted the correct answer. For the submission to be valid, the user must be an active D.Buzz member and has not edited their comment with the answer. The contestant who wants to change their answer must first either delete their previous answer, or edit it such that it points to their new answer. For more information, see #3.
7. The answer does NOT need to be accompanied by its solution or explanation. However, showing the solution and its explanation might help in case the participant's answer appears different from the actual answer. This also allows the participant to impress the audience (assuming their answer is correct) 😆!
8. The math problems to be posted by me would normally be correctly answerable by a competent high school student. The problems will usually come from algebra, geometry, trigonometry, probability, and statistics as they are posted in high school math contests, but may also be from differential or integral calculus.
9. Answers must be in lowest term (if fractional) and have the appropriate units (when applicable) unless specified in the problem. Answers not following this shall be considered incorrect.
10. Every winner for the day shall receive 1 HIVE directly to their Hive account. That is soon after the 24-hour answering period for the correctly-answered problem has passed. If nobody won for the day, see #5.
11. I will not tag any user on every Math problem I post, except supporters (such as @dbuzz). That is to help make sure that no participant gets special notifications for my problems posted which they otherwise might miss.
12. I will not reply to any participant's comment with the answer until after the 24-hour answering period has passed. This is to help avoid influencing the answers of any participant. I may still upvote any comment with the answer, regardless of whether the answer was correct or not.
13. My decision as to what the correct answer is shall be final. Participants are nevertheless encouraged to prove that their answer is correct in case it is not accepted.
14. I may change these rules anytime. Please read these rules from time to time, especially if the user is a participant on this mini-contest.

Based on the performance of the mini-contest and feedback from the participants and supporters, I will decide whether to extend the contest, make another Math mini-contest with slightly updated rules, or not host another contest at all.
 

Mention: @paultactico2
Special mentions: @chrisrice and @jancharlest 😎