Last month we posted a PoSWW on a 2022 Queensland MCQ exam question, for which the accompanying exam report indicated the wrong answer. It is depressingly unclear why QCAA had not been previously alerted to the error, but a couple weeks after our PoSWW appeared, QCAA updated their exam report: in the amended report QCAA indicates the correct answer (p 27), and they also indicate in a footnote that the correction had been made.
For QCAA to have done this was professional and classy. It was also important. The uncorrected report invited, effectively demanded, a mathematical misconception (on inflection points); by correcting the report, QCAA ensured that their exam-report could no longer be relied upon as an authority for this misconception.
This one comes courtesy of Mystery Fred. The diagram above is for a Circle Gaps Brainteaser, and appeared online last week as part of Double Helix, CSIRO‘s science magazine for kids. The text for the brainteaser (as if it matters) is as follows:
What is the area of the orange star in the centre? The blue circles each have an area of 3 square centimetres, and the big square has sides that are 4 centimetres long.
A comment on the post makes it clear that the choices of sidelength and area were purposefully made.