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Homework Problems F4/F6 (math challenge ll-A combinatorics AMC 10)

 
 
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Homework Problems F4/F6 (math challenge ll-A combinatorics AMC 10)
by Lucas Sha - Saturday, January 28, 2017, 12:51 PM
 

I have a couple of questions about these two problems. Firstly, for F4, is there a typo? (Since this is a "quick response" sort of question), I thought the solution to the problem would basically be (1+2)^7 = 2,187, however, the last term is not 2^7 = 128, but instead 2^14 = 16,384, so I wanted to clarify whether this was intended or not. Secondly, I am stuck on F6, and am just wondering whether "NO" would be a valid answer or not.


Thanks!

 
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Re: Homework Problems F4/F6 (math challenge ll-A combinatorics AMC 10)
by - Sunday, January 29, 2017, 4:25 PM
 

Apparently, I found a so-called formula where $a_n$ is the same as $a_{n \pmod4},$ if you are given $a_0$ through $a_3.$ 

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Re: Homework Problems F4/F6 (math challenge ll-A combinatorics AMC 10)
by David Reynoso - Monday, January 30, 2017, 10:59 AM
 

Hello!


- On F4 there is indeed a typo, the last term should be $128$.

- For F6 I'm pretty sure that in your case "NO" would not be an appropriate answer: I know YOU can definitely find a pattern to write the "general term". Just make sure to write carefully the first few terms and follow Sophie's advice, she seems to have a good idea over there.


Cheers,

David