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November 3rd, 2016, 01:55 PM  #1 
Newbie Joined: Oct 2016 From: UK Posts: 7 Thanks: 0  Arithmetic Sequence & Geometric Sequence Question
I can't formulate a method for the following question: An arithmetic sequence is defined by un = 12n  7 and a geometric sequence is defined by vn = 0.3(1.2)^(n1). Find the least no. of terms such that vn > un. Could somebody help me out? 
November 3rd, 2016, 03:17 PM  #2 
Global Moderator Joined: Dec 2006 Posts: 18,845 Thanks: 1567 
For n = 41, 12n  7 = 485 and 0.3(1.2)^(n1) = 440.9... For n = 42, 12n  7 = 497 and 0.3(1.2)^(n1) = 529.1... Hence the answer is 42. 

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arithmetic, geometric, question, sequence 
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