The second term of a geometric series is 4 and the sum to infinity is 18.
Find the two possible values of rrr.
Find the corresponding two possible values of aaa.
Given that r r\,r takes the smaller of the two possible values, find the smallest value of n n\,n for which Sn>17.9S_n > 17.9Sn>17.9.
22 exam-style questions on Edexcel A Level Maths 3.4 Geometric Series. Each one has a worked solution and a mark scheme showing where the marks go.