math

I looked around and found some papers related to Ruggles and Brodie’s 1947 Economic Intelligence paper.

Computer Mad Scientist Hillel Wayne has taken up knights and knaves problems with his favored tactic, Formal Methods.

Found a puzzle on the notorious Futility Closet web site.

Here’s Futility Closet’s puzzle. Mr or Ms Closet decided to call the puzzle “Gun Control”. I don’t know if they chose the title to skirt controversy or something.

Problem Statement

Marksman A hits a certain small target 75 percent of the time. Marksman B hits it 25 percent of the time. The two of them aim at that target and fire simultaneously. One bullet hits it. What’s the probability that it came from A?

One of my kids passed along a logic problem.

Another programming interview question from the Daily Coding Problem email list. I received it as #1608.

Daily Coding Problem: Problem #1608 [Medium]

This problem was asked by Microsoft.

Write a program to determine how many distinct ways there are to create a max heap from a list of N given integers.

For example, if N = 3, and our integers are [1, 2, 3], there are two ways, shown below.

  3      3
 / \    / \
1   2  2   1

Repo for my code.

Oh look! A knights and knaves puzzle in a low rent kid’s funny papers strip. Can we solve this puzzle with the method of Raymond Smullyan’s Og and Bog problem? Let’s find out.

Make one box of mac-n-cheese, kids scarf it and clamor for more.

In my post about Raymond Smullyan’s Og and Bog puzzle, I wrote:

Smullyan has a clever solution in the back of Logical Labyrinths, but I’m going to whittle the puzzle down to a size I can hold in my head, because I like procedures to solve puzzles. Having a procedure keeps me from making mistakes, and developing the procedure helps me understand the underpinnings of all problems.

I thought of something that makes Smullyan smarter than I believed.

Here’s a video (youtube of course) review of both Starship Troopers the movie, and Starship Troopers the book.

It’s long, but worth it.