The second term of a geometric series is 3.75 and the sum to infinity is 20.
Find the two possible values of rrr.
Find the corresponding two possible values of aaa.
Given that r r\,r takes the larger of the two possible values, find the smallest value of n n\,n for which Sn>19S_n > 19Sn>19.
Practise Edexcel A Level Maths 3.4 Geometric Series with exam-style questions for A Level Maths. 27 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.