In a sustainable construction project, the number of solar panels installed during each of the first three months is represented by the following expressions:
4k−1,7k−5,12k−194k - 1, \quad 7k - 5, \quad 12k - 194k−1,7k−5,12k−19
Show that k=5k = 5k=5 is the unique value for which these monthly installation figures form an arithmetic sequence.
State the number of panels installed in the first month.
Determine the common difference for this sequence.
The total number of solar panels installed after NNN months is given by SNS_NSN.
Given that SN<25 000S_N < 25\,000SN<25000 SN+1>25 000S_{N+1} > 25\,000SN+1>25000
Find the value of NNN.
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.