300 posts!

[geodave]

Problem: Break a 40 kg weight into 4 pieces such that those pieces can then be used to measure any (integer) weight from 1 to 40 kg using a balance.

Solution uses balanced ternary (digits: -1, 0, +1).

- Madhav.

Sorry to spoil this for others (not really!), but powers of three is the answer. You have to use a balance, of course, to do the measuring.

Nice problem, since there isn't really an equivalent in other bases.