Poor Alex Bellos
Normally, I'm glad when the media talks about math, even if it is simply the latest "Super-Hard problem from Asia that All of Us Stupid American Adults and Brits Won't be Able to Solve but Their 8 Year-old Do Routinely."
Throw in "I gave it to a mathematician and he couldn't solve it either" and you've got an instant viral hit, apparently.
All right, rant over.
What's the error?
Oh, and solve it if you want, too. It's not really that hard. Further questions: