MOU:
"ah, hats, my favourite (except for rivers crossing)"
"250 days is needed for them to find out - or after 249 days they will figure it out if first day is 0."
You are good, very good.
Mark:
So, there was one $1 bill.
Is also very good.
Whim, is this what you are after?
2, 23, 13, 12, 4, 21, 15, 10, 6, 19, 17, 8, 1, 3, 22, 14, 11, 5, 20, 16, 9, 7, 18
2 Know or not 2 Know
Two whole numbers, m and n, have been chosen. Both are unequal to 1 and the sum of both is less than 100. The product, m × n, is given to mathematician X. The sum, m+n, is given to mathematician Y. Then both mathematicians have the following conversation:
X: I have no idea what your sum is, Y.
Y: That's no news to me, X. I already knew you didn't know that.
X: Ahah! Now I know what your sum must be, Y!
Y: And now I also know what your product is, X!
The Question: What are the numbers m and n
Here are three answers:
1. Answer A
2. Answer A or B
3. Answer B or C
The Question: There is only one correct answer to this question. Which answer is this