DoN. Nichols wrote:


Assuming that all three numbers could be any of the 100, that
leaves 1,000,000 combinations to try. Normally, you are advised to
avoid number near zero (especially on the last one, but assuming that
you avoid 98 through 02, that still leaves 857,375 combinations to try.
(And also consecutive numbers should not be too close to each other,
which reduces the count a bit more, but not really enough. :-)

Well, Richard Feynman was able to crack the safes at Los Alamos
in a couple hours, and I assume they were of similar specifications.
Not clear what tricks he used.

Some of these have all sorts of suicide devices in them, such as
tempered glass plates that shatter when you drill in the wrong place,
and totally jam the works. You then have to saw the entire door in
half to get it open.

Jon