2009 AMC 8 Problem 5
Attempt Problem 5 of the 2009 AMC 8 below, then check your answer against the professionally curated solution from LIVE by Po-Shen Loh. You can also try the full timed exam, view all 2009 AMC 8 solutions, or check the answer key.
All problems are used with official legal permission of the Mathematical Association of America (MAA).
5.
A sequence of numbers starts with and The fourth number of the sequence is the sum of the previous three numbers in the sequence: In the same way, every number after the fourth is the sum of the previous three numbers. What is the eighth number in the sequence?
Answer: D
Small hint:
Generate the sequence one term at a time.
Big hint:
Each new term is the sum of the previous three terms.
Solution:
The sequence begins
The next terms are and
Thus, D is the correct answer.
Problem 5 in other years
- 1985 AMC 8
- 1986 AMC 8
- 1987 AMC 8
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