CAIE P1 2024 November — Question 10

Exam BoardCAIE
ModuleP1 (Pure Mathematics 1)
Year2024
SessionNovember
TopicGeometric Sequences and Series

10 An arithmetic progression has first term 5 and common difference \(d\), where \(d > 0\). The second, fifth and eleventh terms of the arithmetic progression, in that order, are the first three terms of a geometric progression.
  1. Find the value of \(d\).
  2. The sum of the first 77 terms of the arithmetic progression is denoted by \(S _ { 77 }\). The sum of the first 10 terms of the geometric progression is denoted by \(G _ { 10 }\). Find the value of \(S _ { 77 } - G _ { 10 }\).