number of permutation of 0,1,..,9 such that odd number are increasing order?
- PopeLv 71 year ago
I see that Φ² = Φ+1 gave you the answer 30240, 16 hours ago. Since you are asking the same question again, I am guessing that you were put off by the special case suggested by 冷眼旁觀.
In fact, there was nothing special about that case at all. It is simply a sequence of numbers, and we have no reason to exclude a leading zero. If you were looking for a tie-breaker, let this be it. The correct answer is 30240. If that is rejected, then the mistake is in the question, not the answer.
- Φ² = Φ+1Lv 71 year ago
This has already been recently answered here: