Charlie is training to run a marathon. Each week he goes for one long run. In Charlie's first long run he runs 10 km. He then increases the length of his long run by 2 km each week. A marathon is 42 km.
Find the number of weeks it takes until Charlie's long run is a full marathon.
Find the number of weeks until the total length of all Charlie's long runs first exceeds 200 km.
308 exam-style questions on AQA A Level Maths 1.7 D: Sequences and series, covering 1.7.1 Binomial expansion, 1.7.2 Types of sequence (A-level only), 1.7.3 Sigma notation (A-level only), 1.7.4 Arithmetic sequences and series (A-level only), 1.7.5 Geometric sequences and series (A-level only), and 1.7.6 Sequences and series in modelling (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.