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Puzzle #214: Can you help me work out the code to my burglar alarm?

Can you solve this week’s arithmetical puzzle, Seven up? Plus the answer to puzzle #213

22 March 2023

#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…

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