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.
231 exam-style questions on WJEC A Level Maths 3.4 Sequences and Series (A-level only), covering 3.4.1 Sequences and Series (A-level only), 3.4.2 Sequences and Series (A-level only), 3.4.3 Sequences and Series (A-level only), 3.4.4 Sequences and Series (A-level only), 3.4.5 Sequences and Series (A-level only), 3.4.6 Sequences and Series (A-level only), and 3.4.7 Sequences and Series (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.