



 
Hi Sam, From your description it seems that the digits 2, 3, 5, and 6 are all used in the first four digits of the pass code If so there are only 24 possible pass codes and you can try them in an orderly fashion. Suppose the first digit is 2. If the second digit could be 3 and the possible pass code are
If the second digit could be 5 and the possible pass codes are
If the second digit could be 6 and the possible pass codes are
Use an analogous procedure for the other three choices of the first digit. Penny  


Math Central is supported by the University of Regina and The Pacific Institute for the Mathematical Sciences. 