Liam starts a training program where he runs 150 km in the first month and increases his monthly distance by 25 km each subsequent month. Sarah also starts a training program; she runs 210 km in the first month and increases her monthly distance by 15 km each subsequent month.
After how many months have Liam and Sarah run the same total distance.
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.