A-Level Maths: Compound Interest and Combined Sequences Explained

Master Combined Progressions for your A-Level Maths exams. Learn how to solve complex sequence problems with step-by-step methods. This session is tailored for Senior 5 and Senior 6 students preparing for their final assessments. We break down the methodology required to handle complex questions where Arithmetic Progressions and Geometric Progressions intersect, ensuring you can tackle these topics with confidence. We focus on practical applications, including calculating interest and analyzing how sequences grow over time. By following these worked solutions, you will strengthen your problem-solving skills for Paper 1 and streamline your UACE revision process. Subscribe for more A-Level Maths lessons and comment below if there is a specific topic you would like us to cover next. In this Pure Mathematics Series Lesson 4, we solve questions that combine Arithmetic Progressions (AP) and Geometric Progressions (GP), then apply GPs to compound interest. Perfect for Senior 5 UNEB exam preparation. We cover mixed AP-GP problems (including UNEB 2018), sum of terms, common difference/ratio, and real-world compound interest applications — depositing once and depositing every year. Watch previous lessons on APs and GPs on the TV Math channel playlist. Chapters: 0:00 Introduction & Channel Overview 8:52 Combined AP & GP Questions 10:11 Question 1 – UNEB 2018 (AP d=3, GP r=2) 25:11 Question 2 – First term equal, sum to infinity 30:58 Question 3 – Same first term, sums of 1st/2nd/3rd terms 43:39 Question 4 – 1st, 4th & 8th terms form a GP 1:04:10 Question 5 – Equal first terms, d = r = x 1:14:10 Applications of APs & GPs 1:15:18 Depositing Once at Compound Interest 1:19:58 Example 1 – Stanley’s investment (200,000 at 15%) 1:25:51 Example 2 – Population growth to triple 1:31:17 Depositing Every Year at Compound Interest 1:49:27 Example 1 – 150,000 yearly for 7 years at 5% 1:58:18 Example 2 – Deposits 2004–2008 at 2% 2:05:45 Example 3 – 300,000 yearly at 4.5% 2:09:58 Example 4 – 5 million yearly at 15% (UNEB 1998) 2:19:42 Example 5 – Jack’s account at 13.5% 2:38:46 Summary & Next Steps Like, subscribe, and share with classmates preparing for final exams. Full playlist, mock papers, and scoring guides available on the channel and at tvmaster.com.