Archive for the ‘Brain Teaser’ Category

Brain Teasers, IV

Wednesday, April 30th, 2008

Complete the following sequence:

34, 77, 154, 605, 1111, ?

This question actually came from a brain teasers calendar, so I can’t take credit. It’s listed as a 7/10 difficulty, but if you’re good with sequences it’s not hard.

Solutions to Brain Teasers I through III

Friday, January 18th, 2008

Solutions to Brain Teasers I, Brain Teasers II, Brain Teasers III. Stop reading now if your still figuring out the solution.

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Brain Teasers, III

Saturday, November 10th, 2007

Suppose you are wiring a surround sound speaker system.  The room’s dimensions are a bit strange:  3 meters tall, 4 meters wide, and 27 meters long (ok, this is a huge room).  You’re in the process of wiring the rear center channel (point A in the diagram below) which is located 2 meters from each wall and 1 meter from the ceiling.  This needs to be connected to the amplifier on the opposite wall (point B) which is 2 meters from each wall and 1 meter off the ground.



Click to enlarge

Speaker wire is incredibly expensive, and you’re trying to find the shortest possible length you can use. The only rule is that the wire must be directly attached (touching) a surface at all times (a wall, the floor, or the ceiling). You cannot leave the wire dangling by cutting through the space of the room.

An obvious (but non-optimal) solution would be to go from the speaker straight up the wall across the ceiling, and down the opposing wall to the amplifier. This would give a length of 30 meters (1+27+2=30). What is the shortest possible path connecting the two points and how much speaker wire must be used?

Special thanks again to Mikhail for the question. Those crazy Russians are full of good brain teasers. Also thanks to Ben Cirillo for drawing up the diagram in the *real* autocad.

Brain Teasers, II

Wednesday, October 10th, 2007

I’m not sure what the “official definition” of a brain teaser is, but I’m not sure if this one qualifies.  It’s really just straight up recognizing the pattern.  It’s more something out of a Mensa test rather than a traditional brain teaser.

This question is taken from (at least in variant form) my Seagate mentor Norm Binger.

Complete the following series by filling in the two numbers represented as question marks.

1, 2, 4, 11, 22, 44, ?, ?, 514

Brain Teasers, I

Sunday, October 7th, 2007

In response to Parisa’s Riddle Me This post, I’m finally getting around to posting a few brain teasers of my own. To start out, here is a simple one I got from Mikhail at work.

Given the following dot configuration:

Connect all four dots using three straight lines such that you draw continuously (one line is connected to the next) and you stop drawing the same place you started.