We have following sequence:
12345, 33552, 45624, 66345, 73557, 45678, 66885, 78957, 99678
What will be the next number?
Answer is known now (@JonMark Perry and @Mark found it). The answer is:
Danger! It is the correct answer:
but they found it by some properties of this sequence not by general rule and this general rule is very different (And it is interesting that this sequence has so many properties!).
Now the question is: what is the general rule?
notice that always two of five digits are the same (but in different place) like in the previous one number.
There are always the same two digits
For example 12345 -> 33552. Next 33552 -> 45624 and so on.
What with other digits?
Because of general rule, the answer (10th number in sequence) is the first one that doesn't pass rule 99678 -> 106890 But it can be fixed if we choose A688A answer.