Date Rewarded: July 31st, 2008.

A Chomby was walking down a path one day when Jhudora appeared in front of it. "Solve this puzzle, and you may pass," she said.

Suppose you have four numbered tiles, one with a 3 on it, one with a 4, one with a 5, and one with a 6.

**What is the largest four-digit number that can be formed by these tiles that is not evenly divisible by 9?** Only submit a four-digit number as your answer; any other information may disqualify your entry.

__Faerie Tales: Cloud Nine__

__Click to show/solution__

A number is divisible by 9 when the sum of its digits is divisible by 9 [1]. If we sum the four given digits: 3 + 4 + 5 + 6 = 18 (which is divisible by 9), there can't be a number of those 4 digits that isn't divisible by 9.

However, if you rotate the #6 tile, you get #9. Now, the sum of the digits is 3 + 4 + 5 + 9 = 21 (which is not divisible by 9). Any 4 digit number that formed by the above digits will not be divisible by 9. Therefore, the answer is the largest number formed by those 4 digits (3, 4, 5, 9). It is 9543.

Results: some (5503-5517) people guessed the correct answer earning themselves 363NPeach.References:

[1] Divisibility rule