# Category Archives: Puzzles

## Spaghetti Puzzle #1

About a month ago, math educator Marilyn Burns tweeted this puzzle: Here's a problem I've thought about for a long time. Not making progress, but I'm still fascinated. Help? pic.twitter.com/r6iagNUn76 — Marilyn Burns (@mburnsmath) December 6, 2015   Spoiler Alert: … Continue reading

Posted in Fun, Puzzles | | 6 Comments

## Puzzle #11: The Answer (Pi-Fingered Aliens)

I posted Puzzle #11 on Pi Day (3/14/15 in the U.S.).  I noted that the sequence of numbers in 3.14159… reflects not just π, but also ten, the base we use for our numbers. The question was: What is 30.12120111…? After no … Continue reading

## Puzzle #11: A Pi Day Problem

I thought of this Pi Day puzzle yesterday* while getting a haircut. I was thinking about this video by Vi Hart: Many people think that π is special because of its infinite digits. Hart disagrees. Most numbers are irrational like π, … Continue reading

Posted in Puzzles | Tagged , , | 3 Comments

The challenge posed by Puzzle #10: Erratic Bond Pricing? was to guess what might be the cause of apparently wild swings in market yields for some municipal bonds with the same issuer and maturity: Besides this blog, I shared the … Continue reading

## Puzzle #10: A Hint

Puzzle #10: Erratic Bond Pricing? asks you what might explain some apparently erratic swings in yields for certain sporadically traded municipal bonds.  I stated that the bonds share the same issuer and maturity date. The puzzle is a bit sneaky, so … Continue reading

Posted in Bonds, Puzzles | | 8 Comments

## Puzzle #10: Erratic Bond Pricing?

At last week’s Municipal Finance Conference in Boston, I made a brief presentation in response to a paper1 that described a new approach to deriving yield curves from municipal bond trade data. The authors have applied neural network techniques to the … Continue reading

Posted in Bonds, Puzzles | | 15 Comments

## Puzzle #9 (Follow-up): Melting Fractals

The song “Let it Go” from the movie Frozen celebrates “frozen fractals.” I suppose a frozen fractal is something like the Koch snowflake. Lately, though, one of my puzzles has made me more interested in melting fractals. The challenge of Puzzle … Continue reading

Posted in Fun, Graphic Presentation, Math, Puzzles, Visualization | | 2 Comments

## Puzzle #9 (Follow-up): Binary Sudoku and the Limits of Visualization

In Puzzle #9: Island of Games, I described an island where a thousand residents enjoy playing three games: Chess, Checkers, and speed-solving of Rubik’s Cube.  Each islander’s skill at each game is assessed with a rating score between zero and … Continue reading

Posted in Graphic Presentation, Puzzles, Visualization | | 5 Comments

## Puzzle #7 (Follow-up): Treasury Island, Part 1

In Puzzle #7: The Mysterious Islands, I told the story of two islands where each individual’s remaining lifespan can be perfectly predicted. The lifespans on Uniformia are evenly distributed, and their average remaining life expectancy will gradually decline over time. … Continue reading