A GCSE-level maths question is so tough even parents couldn't get it right.
This week, Rishi Sunak spoke about the importance of improving numeracy, as he promised to make it a central objective of the UK education system.
The Prime Minister said: "One of the biggest changes in mindset we need in education today is to reimagine our approach to numeracy. Right now, just half of all 16 to 19-year-olds study any maths at all.