Please reconsider is the title of my new book (out September 5th) and also my advice for today’s puzzle.
1. Hello Duckies
There are two ducks in front of two ducks, two ducks behind two ducks, and two ducks in between. What is the minimum number of ducks?
2. The concentric conundrum
Imagine walking in a circle around Big Ben. For the purposes of this question, we’ll assume you can walk on water.
If the radius is 1km, you will walk approximately 6.28km
If the radius is 100km, you will walk about 628km
If the radius is 10,000km, would that mean walking approximately 62,800km?
(The circumference is the radius times 2 times pi, which is 3.14 to two decimal places.)
3. Hang it with a string
A bottle of water is suspended from the ceiling by a string, with the bottle’s handle also hanging from the same type of string, as shown in the photo below.
Pulling the handle down will break the string. Which one?
a) The top one
b) The bottom
c) They break at the same time
In each of these three questions, the obvious answer isn’t the right one (or maybe it is, but I’m double-bluffing).
Of course, I hope you’re all wrong. First, I have to respond to the headline. (To be honest, it was true when I was the only reader of this column.) Are you up to the challenge?
We’ll bring you the answer at 5pm UK time, so in the meantime, no spoilers please – let’s discuss the ducks!
Puzzles that seem very simple but surprise us are, in my opinion, the most enjoyable kind of puzzles. Here are 70 of my favorite examples. Please reconsider. (Except for today’s.) There’s something irresistible about puzzles that subtly mislead us or reveal something unexpected about the world.
The book won’t be released until September 5th, but you can already pre-order it. do not Think about it: pre-orders help build momentum for your book. Mardle In 2024!
Think carefully: Solve a simple puzzle that (almost) everyone gets wrong By Alex Bellos (Square Peg, £12.99). To support the Guardian and Observer, order your copy here. The Guardian BookshopShipping charges may apply.
Thanks to Fabio Ciuffoli for first teaching me about ducks and to Nikolai Andreev for teaching me about circles.
I’ve been putting out puzzles here every other Monday since 2015. I’m always looking for great puzzles, so if you have any suggestions please email me.
