Bob Baxley, a soon-to-be-loyal MR reader, asks me the following question:

In considering entering in an online drawing for a bicycle, I read the complete rules. The contest is billed as a random drawing of those entered. But what struck me is that "Before being declared a winner, the selected entrant must first correctly answer, unaided, a time-limited, arithmetical, skill-testing question."(http://www.cervelo.com/contestrules.aspx)

Curious about the occurrence of this rule in other contests, I Googled this long phrase and it turns out it is very common in contest drawings: (http://www.google.com/search?hl=en&rlz=1C1GGLS_enUS291US305&q="correctly+answer,+unaided,+a+time-limited,+arithmetical,+skill-testing+question."&btnG=Search). Shorter snippets of this phrase return even more Google hits.

Any thoughts on why this stipulation is listed in the rules?

Maybe his contest is offering up this question to me. But I cannot answer it unaided. Help!