Fun & Games
Aha! Puzzle This


Radar Date

On October 2, 2001, the date in MM/DD/YYYY format was a palindrome (the same forward as backward): 10/02/2001.

When was the last date before 10/02/2001 that this phenomenon occurred?

Crystal Orbs

You have 2 identical crystal orbs. You need to figure out at what height an orb can fall from a 100-story building before it breaks. You know nothing about the toughness of the orbs: they may be very fragile and break when dropped from the first floor, or they may be so tough that dropping them from the 100th floor doesn’t even harm them.

What is the least number of orb drops you would have to do in order to find the lowest floor they break on? In other words, what’s the most efficient way you could drop the orbs to find your answer?

You are allowed to break both orbs, provided that in doing so you uniquely identify the correct floor.

Poison Pills

The evil king from an earlier MAKE puzzle sends his own assassin to take care of the evil queen who tried to poison him. Of course, her trusty guards catch the assassin before any harm is done. The queen notices that the assassin is quite handsome, and she doesn’t really want to punish him with death. She decides to test his wisdom.

The queen gives the assassin 12 pills that are all completely identical in shape, smell, texture, and size, but 1 pill has a different weight. The queen gives the man a balance and tells him that all the pills are deadly poison except for the pill of a different weight. The assassin can make 3 weighings and then must swallow the pill of his choice. If he lives, he will be sent back to the bad king’s kingdom. If he dies, well, that’s what he gets for being an assassin.

Only 1 pill is not poisonous, the one that has a different weight. The assassin does not know if it weighs more or less than the other pills.

How can he save his skin?

Michael H. Pryor

Michael H. Pryor is the co-founder and president of Fog Creek Software. He runs a technical interview site at

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