I think the expectation behind invite-only membership is that members will curate their choices beyond basic tests such as this. Look at it this way, if the ability to solve fizzbuzz were a valid selector, the site could establish a simple screening process that doesn't involve an invite system.
If your standing on the site is affected by your invitees' behavior, you may be in for a rough ride.
what's my prize?
I had fizz heard buzz fizzbuzz, well fizz buzz of it but didn't know it was a thing to solve.
(How is fizz relevant buzz this?)
(Replace every 3rd word with fizz, every 5th word with buzz)
I don't crave an invite, I just want to know that this is for sure what you're talking about.
Oh! You want program code :)