brainteaser

They are all elements of an annual brainteaser for UK school children set by the nation's spy agency.

For the more numerically minded, the next brainteaser may be more appealing...

It is less about creating the perfect brainteaser and more about showcasing a flawed family with outsize personalities.

Rob Tanenbaum put together a playlist of 10 of his best-known songs, and Jon Pareles wrote a lovely appraisal that begins with quite a musical brainteaser: “Has there ever been a more purely likable pop figure than Tony Bennett?”

It turns out that if you want to solve a brainteaser, it helps to have a brain.