A start-up company tracks its daily net cash flow, CnC_nCn, in pounds (£\pounds£). The cash flow follows an arithmetic sequence with first term aaa and common difference ddd.
The total net cash flow over the first 12 days is £\pounds£ 432.
Show that 4a+22d=1444a + 22d = 1444a+22d=144.
Given that the total net cash flow over the first 30 days is £\pounds£ 0, determine the total net cash flow over the first 15 days.
SnS_nSn represents the sum of the daily net cash flow for the first nnn days. Explain why the value you calculated in part (b) is the maximum value of SnS_nSn.
Practise Edexcel A Level Maths 3.2 Arithmetic Series with exam-style questions for A Level Maths. 38 questions, matched to the Edexcel A Level Maths (9MA0) 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.