Question 643787: For the geometric sequence, what is the least value of n such that the nth term is greater than a 1000.
16, 24,36
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! For the geometric sequence, what is the least value of n such that the nth term is greater than a 1000.
16, 24,36
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a*r^(n-1) >= 1000
16*(3/2)^(n-1) >= 1000
(3/2)^(n-1) >= 62.5
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Take the log of both sides:
(n-1)log(1.5) >= log(62.5)
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n-1 >= 10.2
N >= 11.2
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Ans: n = 11
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Cheers,
Stan H.
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