300 students are asked how they get to school. All of the students either walk to school or get the bus to school.
50% of the students walk to school. 50% of the students are boys. 20% of the students are boys who get the bus to school.
Work out how many girls walk to school.
Hence, work out the percentage of the girls who walk to school.
159 exam-style questions on OCR GCSE Maths Two Way Tables. Each one has a worked solution and a mark scheme showing where the marks go.