A GCSE maths question that has stumped many students was shared by secondary school maths teacher Natasha Hall. The puzzle is easy to solve but also easy to misread under exam pressure.
The question and the common mistake
The past AQA exam paper question reads: "A bag contains 72 blue beads and some red beads. Blue beads : red beads = 4:5. Work out the number of red beads."
Natasha explained: "Most people read this as meaning that there are 72 beads and so they add up the two ratios and divide 72 by 9 (4 + 5). 72 divides by 9 to give 8 and then 8 × 5 (number of red beads) = 40."
How to get the correct answer
However, the question states there are 72 blue beads. The correct method is to divide 72 by 4 (the number of blue beads) to get 18, then multiply 18 by 5 to get the correct answer: 90.
Natasha noted: "There's nothing wrong with the question, but it's easily misinterpreted."
Previous exam errors
In June 2026, an exam board apologised after finding mistakes in "all versions" of a GCSE science paper. Tes magazine reported that England's largest exam board, AQA, apologised for the mistake and reported the error to exams regulator Ofqual.
Michael Turner, the exam board's chief commercial officer, stressed that AQA "has processes in place to make sure that no learners are disadvantaged by it". He said in an email to exams officers: "We're sorry to let you know that there was a mistake on all versions of the GCSE Combined Science Trilogy higher paper 2, which students sat on Monday 15 June 2026."
In one question, students were asked to "calculate the mass of a system", but the answer prompt stated "mass of glider" – which would only make up a portion of the system.
It was the second error in a little over a week. Earlier the same month, students sitting a foundation-tier GCSE maths paper opened their sealed exam papers to discover an insert with information intended for another paper.
One teacher told Tes that schools had heard nothing from AQA about the incorrect inserts, saying: "In this series of exams we've had two erratum notices for minor typos (geography and physics) but nothing at all for this. Schools only found out via text and email from colleagues working elsewhere."
Exams officers downloaded new inserts and rushed to print them. Some disruption to smooth starts but exams started within the rules - still nothing from AQA now.
