Nine Queensland high schools taught year 12 students the wrong topic for today's external ancient history exam, but the education minister says the students will "not be disadvantaged in any way".

Education minister John-Paul Langbroek said the exam results for the 140 students who learnt about Augustus instead of Julius Caesar would be scaled with the internal assessments they have already completed worth 75 per cent.

"For all of us, as parents or students, who have been through situations like this it would be extremely traumatic," he said.

"I want to reassure these students and their parents and the teachers affected that we'll be making every investigation into how this happened."

" I'm very unhappy about the situation developing as it has for the stress of course for everyone, th

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