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# answer question 1 to 8 only.
Topic: Arithmetic and geometric series.
1. Determine the number of terms and the sum of the sequence: 5, 11, 17, … , 83. (14, 616)
2. The fourth term and the 8th term of an arithmetic sequence are 16 and 32 respectively. Find: a) Common difference (4) b) the sum of the first 20 terms of this sequence (840)
3. The 3rd term and the 7th term of an arithmetic progression are 11 and 27 respectively. Find the sum of the first 20 terms. (820)
4. The first term of an arithmetic sequence is -5 and its last term is 40. If its common difference is 3, find: a) the number of terms in the series (16) b) the sum of all terms (280)
5. The 6th term in arithmetic series is 23 and the sum of the first 6th terms is 78. Find its common difference. (4)
6. The first term of an arithmetic sequence is 2. The sum of its first 30 terms is 1800. Find the 20th term.
7. Allen borrows RM14,500 without interest from a friend and agrees to repay his debt by 10 instalments. He pays RM1,000 as the first instalment and then increases every successive instalment by RMd from the preceding instalment. Find the value of d. (100)
8. A building has 30 floors. The cleaning cost for the first floor is RM100, the 2nd floor is RM150, and the third floor is RM200, and so on. Find the cleaning cost for the whole building. (24750)
9. Given the sequence: 5, 10, 20, …, 2560. Find the number of terms. (10)
10. The 3rd term and the 8th term of a geometric progression are 18 and 4374 respectively. Find the first term and the common ratio. (2, 3)
11. The 3rd term of a geometric progression is 2 and 6th term is 16. Find the first term and the