Welcome to the second instalment of my new puzzle series. Every second Monday I’ll be posting some kind of brainteaser, usually mathematical, here on the science blog network. I hope you enjoyed solving today’s odd-one-out problem, because it was meant to be funny, as well as fun. The puzzle was written by Joseph Yeo Boon Wooi of Singapore’s National Institute of Education, originally for a test paper in the Singapore and Asian Schools Math Olympiad. Last time I asked you about Denise and her birthday. He has also hidden a fun little nugget - what he calls an “Easter egg” - in this one. Go, guzzlers, go! Facebook Twitter Pinterest As well as being the creator of the Cheryl puzzle, Joseph Yeo Boon Wooi also stands out in the mathematical community for the large number of o’s in his name. You can also check me out on Twitter, Facebook, Google+ and my personal website.
– Last month the Internet went nuts trying to figure out Cheryl's birthday. Today, Alex Bellos is back in the Guardian with two more stumpers, what he calls the "second installment" in his let's-drive-everyone-mad puzzle series (the first was a sequel to the Cheryl's birthday puzzle). The reason it comes with the title "Are you smarter than a Hong Kong six-year-old?" is that Bellos actually took the first puzzle from an admissions test for first grade in Hong Kong. You only have 20 seconds to solve it, just like the schoolkids did. Got it? We'll direct you to the answer, but not before you head to the Guardian to view the second visual doozy. All you have to do there is figure out which shape is the odd one out. Answers to both here. (Click to read about the Internet's most mysterious puzzle.)