4-digit Hotel Room Safe Code

Tuesday 1st January 2019

I spent part of the holidays driving around the northern hills of Thailand. Each night I stayed in a different hotel and each of these hotels had very similar safes in the rooms. A four digit code number was required to use the safe. I decided to choose a number such that the first digit was the number of noughts in the code, the second the number of ones, the third the number of twos and the fourth the number of threes. When I realised there was more than one four-digit number that satisfied this requirement I chose the largest one.