An environmental initiative requires a company to make monthly carbon-offset payments. The payment in the first month is P1=£4,250P_1 = £4,250P1=£4,250, and the payment in the second month is P2=£5,375P_2 = £5,375P2=£5,375. The monthly payments PnP_nPn follow an arithmetic progression. The final payment made is £54,875£54,875£54,875.
Find
the total number of months for which the company made payments,
the total sum of all carbon-offset payments made over the duration of the initiative.
Practise AQA A Level Maths 1.7 D: Sequences and series with exam-style questions for A Level Maths. 267 questions 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), matched to the AQA A Level Maths (7357) specification and written in Paper 1, Paper 2 and Paper 3 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.