What's the Answer to a Math Question Stumping Thousands Students?

It's a math question that has provoked outrage, confused people on Twitter and even prompted thousands of students to sign a petition asking for the chance to resit the entire exam — so think can you figure out the probability riddle that's perplexed so many British pupils?
The tricky question appeared on Thursday on the GCSE exam, which is taken by students in secondary schools in the UK around ages 15 or 16. It's a state exam, so about 500,000 took the test.
And so it goes: "There are n sweets in a bag. Six of the sweets are orange. The rest of the sweets are yellow. Hannah takes a random 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."
If you still have no idea, just look it up on Google--the solution to all our problems when not in a test taking environment? this video uploaded to YouTube goes through the whole process.