GCSE maths SHOULD be challenging, argues Rachel Riley, after thousands of students complain online

It was a maths exam question about sweets which left a bitter taste in the mouths of thousands of GCSE students.

But according to Countdown's resident maths expert Rachel Riley, the question regarding Hannah and her sweets - which ended with a demand for the student to prove an equation - should be "textbook" for teenagers.

Students took to social media in their droves to complain about the question, with many arguing that the question was far above what they had been prepared for.

But Ms Riley defended the inclusion of the problem on the test, telling ITV News the puzzle was "standard textbook stuff" for 16-year-olds - and said the purpose of the exam was to challenge students.

ITV News correspondent Neil Connery reports:

The problem is as follows:

Read: Quiz: Could you pass GCSE Maths?

Explaining how the problem should be solved, Ms Riley said she was delighted that people were talking about maths - swapping ideas and even trying out problems for themselves.

Exam board EdExcel has said the paper aimed to test the full range of students' abilities, and it is understood the question was aimed at those aiming for top marks with A and A* grades.

Read: #Edexcelmaths: Students mock their GCSE exam on Twitter