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This week two of the math questions were wrong. Ons was "Sreejato's ordered pairs", the other one was "Strings with brackets". Sreejato's problem as it was first posed was simply impossible (the assumption f(n)=12 was impossible, it always had to be odd). And yet there were 60 people orso that had solved the problem...by guessing the correct question! Two days later the question changed to f(n)=13. The second question was actually possible as it was first posed, but then it said my answer was wrong. Then again I saw this question change (even twice) during the week. I don't think the idea of the site is for people to guess correct questions. It would be sad if people get annoyed and started dropping out.


Note by Michael May
3 years, 2 months ago

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The question "Sreejato's ordered pairs" was indeed wrong, and we had a typo in the question.

The question "Strings with brackets" was posed correctly. As some students were confused with the exact meaning of the last phrase, I decided to write out the condition explicitly. The meaning of the question has not been changed in the different versions. If your answer was marked wrong, you must have taken an incorrect interpretation of the condition. Calvin Lin Staff · 3 years, 2 months ago

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@Calvin Lin Initially the question said "for k=1,2, we see k('s before k)'s?" I don't really want to comment on ongoing problems, but for k=2 it says we see 2 ('s before 2 )'s, which gives a little less solutions as to how the question is posed now. "The first ( occurs before the first )" and "the second ( occurs before the second )?" Or maybe I'm just still confused about the original question. Anyway, there is no confusion possible with how it's stated now, so that's good.

-michael Michael May · 3 years, 2 months ago

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As I have mentioned in the discussions thread of the solution, the error in the question was a typing error. In my original question, I had asked for the smallest prime power \(N\) satisfying \( f(N)= 7 \). It was changed to \(12\) when it was published, which is most possibly a typo. Sreejato Bhattacharya · 3 years, 2 months ago

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@Sreejato Bhattacharya Don't you mean \(f(N)=13\)? Tim Vermeulen · 3 years, 2 months ago

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@Tim Vermeulen In his original version, he gave \(f(N) = 7 \), which had an answer of 8. I felt that this was too close 7 which would make it lucky guess. Hence, I decided to change the question to \(f(N) = 13 \) instead. At this point, I introduced a typo and wrote \( f(N) = 12 \) instead. This error slipped through our proof-reading. Calvin Lin Staff · 3 years, 2 months ago

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