That's standard practice for any contest in Canada.
There's a law up here that says nothing can be given away for free, and that the recipient of the item/gift/prize/whatever must do some kind of "work" in order to receive it.
So, the easiest way to make someone "work" for a prize, is to have them answer a "skill testing math question". It's a dumb law in these times, with all the promotions going on, but I guess there was a reason for its creation way back when.
Also, unfortunately, if you read the rules fully, it says the contest isn't open to residents of Quebec. So . . . whew, I'm still eligible, I live in Ontario. I'm so glad I get to participate in a contest, for a change. But I feel sorry for Quebec residents and international fans who are left out in the cold, once again.