My friend Gus shared this ingenious demo of an old puzzle on twitter. Check out the short video below and see if you can tell what’s happening.
The original incarnation of today’s puzzle talked about winding a clock but who even knows what that means anymore? Here’s a more modern formulation. While you’re asleep one night, there’s a power outage…
This puzzle is fun and not too difficult if you take your time.
I was in sixth grade when I first saw this puzzle and it captivated me for a few days, because I have no problem wasting ridiculous amounts of time on useless activities (like this blog).
How quickly can you find out what is unusual about this paragraph?
How surprised should we be to find a common birthday in a random group of people?
In front of you are three boxes. One contains only apples, one contains only oranges and one contains a mix of apples and oranges.
I like puzzles that are easy to state and don’t require a lengthy explanation. Today’s puzzle falls into that category.
One of the nice things about living in Seattle is that on clear days we get a great view of Mt. Rainier. Considered an active volcano, Mt. Rainier is the third-highest mountain in the lower 48 states at 14,411 feet, and the most ice-covered, with 25 major glaciers covering 34 square miles (source).
Have you ever heard of a palindrome? It’s a word, phrase, sentence (or more) that’s spelled exactly the same way backward and forward. Here are a few well known palindromes:
You and two of your friends (not facebook friends, real world friends, remember those?) are playing a game. The dealer holds three cards, which may contain any number of aces (0, 1, 2 or 3). Each player is dealt a card face down, and asked to hold their card up against their forehead so the value side is facing out.
This is another one that Microsoft and other companies have used as an interview question but it’s a little easier than some of my recent brain benders.
Imagine you have nine uniformly sized white balls, eight of which weigh precisely the same amount, and one is decidedly heavier or lighter than the rest.
Imagine a very wealthy and eccentric friend (which is the best kind of friend to have) offers you the following choice:
In front of you are four cards on a table, which look like this:
For the past 63 years in a row, babies born in the US have been slightly more likely to be a boy than a girl, at a rate of roughly 51% to 49% (source).
Imagine that in a future era humans decide to build a high speed train circumnavigating the globe at the equator.
You’re a pharmacist and you’ve just taken delivery of ten bottles of 1,000 pills each.
Today we’re doing a good old-fashioned trivia quiz with a topical theme: every answer has something to do with Egypt.
Three co-workers are on a business trip. They arrive at their hotel only to learn their reservations have been lost. The desk clerk tells them there is only one room still available but it can be shared by the three companions.
Today’s puzzle is said to have been devised by Albert Einstein, who supposedly claimed that 98% of the population could not solve it.
I first read about today’s puzzle as a young boy and it’s stayed with me all these years later.
Imagine tossing a coin repeatedly until you get a certain pattern, let’s say HTT (head, tail, tail).
I like puzzles that are easily stated. Today’s challenge, from the fertile mind of the late, legendary puzzle master Martin Gardner, is a model of simplicity:
I first heard today’s puzzle several years ago from a co-worker who had recently returned from a job interview at Microsoft, where he’d been asked to solve this one in real time.