Learn about and revise vectors and how they can be can be added, subtracted and multiplied by a scalar with this Bitesize GCSE Maths Edexcel guide.

Here's your chance to have a go at some of the toughest A-level maths questions in papers from the past six years from exam boards AQA, Edexcel and OCR.

The pupils who all sat the Edexcel maths paper Wednesday morning took to the social networking site after being stumped by the probability question.