3 ms·
1. A puts amulet in the safe, puts lock on it, sends to B. B puts lock on it, sends back to A. A unlocks his lock and sends it back to B. B unlocks and receives
by huangm 17y ago
1. A puts amulet in the safe, puts lock on it, sends to B. B puts lock on it, sends back to A. A unlocks his lock and sends it back to B. B unlocks and receives the amulet.
2. Take 20 coins aside, and flip them - this is one group. Take the 80 remaining coins - this is the second group. If there were X (0 \leq X \leq 20) queens in the first group, then there were 20-X queens in the second group. Since we flip the 20 coins in the first group, there are now 20-X queens in the first group as well.
- eggoa 17y agoI guess that's the right answer, but it's not really satisfying. If the servants can walk off with the safe to crack it at their leisure, how is it secure?
- huangm 17y agoThe moral here is that the more colorful you try to make your logic puzzle, the more implausible the correct solution will be.