## Welcome to BrainDen.com - Brain Teasers Forum

 Welcome to BrainDen.com - Brain Teasers Forum. Like most online communities you must register to post in our community, but don't worry this is a simple free process. To be a part of BrainDen Forums you may create a new account or sign in if you already have an account. As a member you could start new topics, reply to others, subscribe to topics/forums to get automatic updates, get your own profile and make new friends. Of course, you can also enjoy our collection of amazing optical illusions and cool math games. If you like our site, you may support us by simply clicking Google "+1" or Facebook "Like" buttons at the top. If you have a website, we would appreciate a little link to BrainDen. Thanks and enjoy the Den :-)
Guest Message by DevFuse

# Fibonacci might have been here

Best Answer nana77, 15 July 2014 - 07:09 AM

Fun

Go to the full post

### #1 bonanova

bonanova

bonanova

• Moderator
• 5891 posts
• Gender:Male
• Location:New York

Posted 15 July 2014 - 07:02 AM

The sequence S1, S2, S3, ... , S10 has the property that every term after the second is the sum of the previous two.

That is, Sn = Sn-2 + Sn-1 for n > 2.

Suppose that S9 = 110 and S7 = 42.

What is S4?

• 0
The greatest challenge to any thinker is stating the problem in a way that will allow a solution.
- Bertrand Russell

### #2 nana77

nana77

Senior Member

• Members
• 519 posts
• Gender:Female

Posted 15 July 2014 - 07:09 AM   Best Answer

Fun