2009 AMC 12B Problem 12
Below is the professionally curated solution for Problem 12 of the 2009 AMC 12B, from LIVE by Po-Shen Loh. You can also try the full timed exam, view all 2009 AMC 12B solutions, or check the answer key.
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Difficulty rating: 1500
12.
The fifth and eighth terms of a geometric sequence of real numbers are and respectively. What is the first term?
Solution:
The eighth term divided by the fifth term is so
The fifth term is so
Thus, the correct answer is E.
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