Here is yet a different kind of puzzle. It will teach you (if you figure it out) how to solve another large class of logic puzzles. Enjoy. It isn't as easy as you might think!

Your Yellow Lab Retriever is having puppies!! You (Bill) watch as she quickly delivers two males. You run upstairs to grab your camera and the doorbell rings - two of your friends (Joe and Bob) have come over to visit. You mention that your dog has just given birth. After a little while you all go downstairs to see how the they are doing. On the way down, you mention to Joe (Bob doesn't hear) that there are two male puppies. When you return, a third has been born... a chocolate!! You now have one of each color. The yellow and black lab puppies (your friends don't know in which order they were born) tumble over each other and Joe notices that those two are boys. You challenge each other: What is the probability that all three puppies are male? Bob overhears the challenge, but he doesn't know the gender of any of the puppies.

Bill, Joe, and Bob all happen to be taking "Statistics 101" together at the local community collage. Over a beer they jot down their answers. They are all pretty bright students (assume they get it right) and competitive (they don't help each other or compare notes). What did they come up with?

If you give up, here is the solution:
http://blogs.sun.com/roller/resources/dcb/SOLUTION_Puppy_Perplexity.html

February 28, 2005 10:38 AM EST Permalink

Here is an interesting little puzzle. It isn't so much a puzzle as a highly counter-intuitive reality. If you run the math to check your assumptions, you might think you've been hit by the Intel Processor computation bug. :-)

To help you out, the average radius of the Earth is about 3,959 miles, and the classic formula is: "circumference = 2 * pi * radius", where "pi" is approximately 3.14156. Polar (3,949.8 mi) and Equatorial (3,963.2 mi) radii are close enough to assume a perfect (smooth) sphere for this problem.

Your company has just completed a massive global engineering project. You've built a particle accelerator, a superconducting supercollider that circumnavigates the globe! A perfectly circular hollow pipe thru which protons and anti-protons are accelerated and smash into each other.

But just before you flip the switch to energize the superconducting magnets, the UN caves to the protest of environmentalists. Seems your pipe is hindering the migration of the revered Banana Slug in the forests adjacent to Santa Cruz (apparently there are a lot of laywers there with nothing better to do, except maybe sue IBM). You are commanded to raise the level of the pipe by 3 feet. Since the shape must remain a perfect circle, you must raise the pipe by this much around the entire length of the 24,850 mile pipe, not just there in Santa Cruz.

Try to guess the length of the segment of pipe you will need to add to raise the level of the supercollider by 3 feet around the entire circumference of the globe (multiple choice). After you've made a guess, go ahead and run the math.

1. More than 5,000 feet
2. 1,000-2,000 feet
3. 100-200 feet
4. Less than 20 feet

Extra credit: What if you wanted to "raise" by 3 feet a circular pipe with a radius equal to the distance between the Sun and Neptune (average radius = 2,798,842,261 miles)?

In case you give up, here is the solution:
http://blogs.sun.com/roller/resources/dcb/SOLUTION_24K_Pipe.html

February 28, 2005 08:00 AM EST Permalink