Hannah and her Sweets: that EdExcel Examination Question…
You may or may not know that yesterday there was a bit of a Twitterstorm of students complaining about an “unfairly difficult” examination question on the GCSE Mathematics paper set by EdExcel.
This is the question:
There are n sweets in a bag. Six of the sweets are orange. The rest of the sweets are yellow.
Hannah takes a sweet from the bag. She eats the sweet. Hannah then takes at random another sweet from the bag. She eats the sweet.
The probability that Hannah eats two orange sweets is 1/3. Show that n²-n-90=0.
Not sure what all the fuss is about. Seems very straightforward. The question tells you that 6/n × 5/(n-1)=1/3 whence the equation follows by a trivial rearrangement. In fact I’m a little surprised the question didn’t go on to ask the students to solve the quadratic equation n²-n-90=0 to show that n=10…
I don’t really know what is on the GCSE Mathematics syllabus these days. In fact I never did GCSE Mathematics, I did O-level Mathematics which was quite a different thing. You can see the papers I took – way back in 1979 – here.Follow @telescoper