June 02, 2007

99 Cent Game

Heidi and David are in Hawaii on vacation and buy a cone of Dole Whip, which comes to $2.01 after tax. The cashier gives Heidi three quarters, a dime, two nickels, and four pennies.

"I hate getting 99 cents of change," says Heidi.

"Ah hah, but then you can play the 99 cent game," replies David.

David explains the rules:

Heidi will arrange her ten coins in a single line, in any order she likes.

Then, starting with David, each of them will take turns taking a coin from one of the two ends of the line, until each has five coins.

In the end, whoever has more money wins.

This simple game is actually pretty fun. You can play it with any handful of coins, and it is not obvious what the best strategy is. But there is a simple winning strategy.

If Heidi gets to place the coins and David goes first, which player has a winning strategy, Heidi or David?

Posted by David at 06:32 PM | Comments (8)

June 06, 2007

Is Toyota the Microsoft of Cars?

Today it is being reported that Honda is dropping the Accord hybrid.

I don't think anybody disputes that hybrids are a growing segment of the car business. But most people believe that hybrids will not take over. The fact is that hybirds appear too complicated and costly to be worth the effort in real economic terms: two engines will always be more expensive than one. So hybrids are being sold as a "feel good" green product - something that you would buy as a second or third car. The Prius is a fashion statement that you can drive to Whole Foods, while chatting on your iPhone.

But for an hard-nosed engineer, hybrids are expensive, ugly adapters. They are destined to fall by the wayside....

Continue reading "Is Toyota the Microsoft of Cars?"
Posted by David at 08:15 AM | Comments (1)

June 12, 2007

Gladwyne Home for Sale

We are about to list our Gladwyne PA house for sale, so please let us know if you are interested in it. Today is moving day, and I have already packed my digital camera, or else I would have snapped a few photos of the house to post here (Update 6/27: Alan has taken a photo so I've posted it below). Certainly you can check it out on Google maps or Microsoft's maps. As an experiment, I am putting information about the house on Zillow and this website as well as MLS.

The house is a unique bit of Gladwyne real estate - there is much more to the neighborhood than just the desirable demographics or the superb school district. So I am posting this web page about it.

First, here is the address...

Continue reading "Gladwyne Home for Sale"
Posted by David at 02:27 PM | Comments (0)

June 18, 2007

99 Cents Solved

Jacek has solved the 99 cent game - you can go read the comments on the previous post if you want to see the trick to winning it. Or just try playtesting Anthony's setup below to get a hint of the winning strategy without peeking.

These coin games are so great. On the second-to-last day of school Anthony had to bring a board game to play. Because of our move, all our board games were packed in boxes - and so he just brought a handful of change instead. No need for Parker Brothers if you want to play Nim or the 99 cent game.

Anthony does not yet know the secret for winning the 99 cent game, but I have taught the secret to Piper. Piper is only five, so she is just learning how to count up the value of coins. But when playing the game, she is utterly unbeatable - it is a remarkable thing to see.

Yesterday Anthony set up a "devious" set of coins to try to beat Piper - we had 75 cents in fourteen coins, and Anthony arranged them like this: (P is for a 1 cent penny, N is for a 5 cent nickel, and D is for a 10 cent dime)


The wonderful thing about Anthony's setup is that when it is played, it looks like Piper is going to lose - until the very end!

Do you know any other cute games that can be played with a pocket full of coins?

Posted by David at 12:21 PM | Comments (2)

June 19, 2007

Got My Number?

I was unable to open a bank account today because somebody else has an account that uses my social security number.

"Have your card handy?" asked the bank manager.

"As a matter of fact, I do."

An hour of phoning around later, the bank is still unable to get in touch with the other person using my number, so no account for me.

At least I am not poor Hilda Schrader Whitcher, whose number was claimed by more than 5000 people after it was printed on a sample card in a wallet sold at Wooworth.

Posted by David at 04:50 PM | Comments (0)

June 23, 2007

Internet-Free Week

After our move, we had no internet access in our house. It's amazing to try to live without the internet for a week - how did we ever do anything without it? We had no idea about how to find out anything, from how to dispose of our trash in Lincoln, to how to contact the contractor who was going to install our internet access.

We did a good deal of talking to strangers in town to discover things like the location of the town dump and the hours. But also we did a lot of using the new 1-800-GOOG-411 service, which I had never tried before.

I was pleasantly surprised - it is quite good! Calling GOOG-411 feels very much like navigating Google Local search with your voice. It had no problems finding our broadband installer even though I had no idea which town around here he is based in. And no charge, and no need to bother a human operator ten times a day.

Posted by David at 11:26 AM | Comments (0)

June 29, 2007

Live iPhone Shows

The iPhone launch is quite the event. Most entertaining blog o the day:

iFixit.com liveblogs the disassembly of two brand-spanking new 8GB iPhones. Ooh, they just figured out how to get the antenna off. Look at that naked circuit board!

Posted by David at 07:34 PM | Comments (2)