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Welcome to perplexus.info, flooble's perplexing puzzle portal. Here, we collect all sorts of puzzles, from simple logic questions and word tricks to in-depth math problems like probability and geometry. Click around and see if your brain is up to the task! If you're new here, make sure you sign up so that you can leave comments and submit your own problems!
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What real value of x satisfies the equation 9^x + 12^x = 16^x?
(No Solution Yet, 0 Comments) Submitted on 2019-12-11 by Brian Smith   
Difficulty: 3 of 5 Bonus: Fibonacci sums (in Just Math) Rating: 3.71
The Fibonacci series 0, 1, 1, 2, 3, 5, 8, 13, in which each number is the sum of the two previous, is defined as F(0)=0, F(1)=1, and F(n)=F(n-1)+F(n-2) for n>1.

What is the sum of F(0)+F(1)+F(2)+...+F(k)?
What is the sum of F(0)^2+F(1)^2+F(2)^2+...+F(k)^2?

(Solution Posted, 13 Comments) Submitted on 2004-07-15 by Federico Kereki   
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