A lot of us adults love a challenge – especially one which asks us to ‘pit our knowledge’ against a child’s.
And recently, with the general appetite for brain-teasers and puzzles, there have been plenty of opportunities.
Unfortunately for many of us, some of the questions and challenges have got the better of us.
The most recent one to have adults confused was posted by a mum on Twitter, and prompted a lengthy old debate about what the answer is and the best way to work it out.
So, what’s the answer?