An exam board has admitted it made a GCSE exam paper too difficult - so had to give students an A* grade for getting just 47% of the marks.
The AQA board was responding to reports that students needed only 49 marks out of 105 on a business studies paper.
All boards adjust the marks needed in an effort to maintain the standard of their exams year-on-year.
An AQA spokesman said papers were carefully designed but sometimes proved more difficult than expected.
In this case "it was a problem paper and it just turned out that it didn't work the way it was intended to," he said.
"They are going to look at it again for next year."
Only one of the three papers in the business studies B syllabus GCSE was involved.
The marks needed on the other two to get an A* overall were 80% and 86%, he added.
Published results show it was taken by 14,791 people, 5.5% of whom got an A*.