Found the rules for the contest...seems legit...a new site that had a Facebook contest...good luck.
https://www.countdownmarketplace.ca/static/docs/rules_EN.b787fb656207.pdf
AWARDING THE PRIZES: The winners will be selected at random from all verified entries received during the Contest Period.
The winners will be drawn from entries received between 12:01 a.m. on August 1st, 2019 EST and 11:59 p.m. on August 31st, 2019 EST by an employee of the Sponsor or Administrator on the following date. The draw for the Prizes will commence on September 1st, 2019.
The selected winners for the draw will be contacted by email and will be required to correctly answer, without assistance of any kind, a time-limited mathematical skill-testing question. In order to be declared a winner, the selected Entrants must also have complied with all Contest rules and sign a Confirmation and Release form confirming compliance with the Contest Rules and acceptance of the Prize as awarded (see paragraph 9 below). If the selected Entrants cannot be contacted within one (1) day of the random draw, does not respond in accordance with the Contest rules, does not answer the skill-testing question correctly or, for any other reason, the Prize cannot be awarded, he/she will be disqualified and will not receive the Prize and another Entrant will be randomly selected as the winner of that Prize.
The Confirmation and Release form is to be completed by the selected Entrant and must be returned to the Sponsor within two (2) days of the notification date indicated on the documents in order to claim the Prize.
It was open to CA and USA, and I assume the math question was for CA...seems like they wish to get your entry verified for possible prize award?