Hannah Sweets: Killer Question Edexcel Maths GCSE

Yesterday hundreds of thousands of teenagers up and down the country sat an Edexcel Maths Exam. I was among them. Over the course of the hours that followed, the #EdexcelMaths hashtag went viral, with the angry GCSE students bemoaning Hannah's Sweets, a strange question about probability. Although some people were upset about Karl's charity, grain containers and conservatory tilings, most of the outrage centered around orange and yellow sweets. I set out to solve the problem, explaining how I went about doing it. If it wasn't for Further Maths giving me lots of practice on these questions, I honestly think that Hannah's innocuous sweets could have been my downfall.

[djonvincent]

This is how I did it:

6/n * 5/n-1 = 1/3

30/n(n-1) = 1/3

n(n-1)/30 = 3

n(n-1) = 90

n^2 - n = 90

n^2 - n - 90 = 0