#214 Seven up!
Set by Mary Ellis
My burglar alarm won’t stop beeping. I need to enter the four-digit code, but I just can’t remember what it is.
I do remember that I chose a number that is divisible by 7. I also know that I chose a number in the thousands. I recall that the numbers formed by the first three digits and the last three are divisible by 7 as well. I also deliberately chose four different digits. Finally, I know that if I add all the digits, their sum isn’t divisible by 7, but if I add …