Sarah is training for a marathon. In the first week, she runs 1.2 km. In the second week, she runs 1.5 km, and in the third week, she runs 1.8 km. She continues this pattern for 30 weeks. Her weekly distances form an arithmetic sequence.
Find the distance she runs in week 30.
Calculate her total distance run over the 30 week period.
20 exam-style questions on OCR A Level Maths 1.4.11 Modelling with sequences and series (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.