## Even Odds

January 30, 2013

The laws of probability, so true in general, so fallacious in particular.
–Edward Gibbon

A puzzle has recently been brought to my attention. It goes like this: “I have two children. One of them is a boy born on a Tuesday. What is the probability that I have two boys?” This puzzle was posed to an audience at the Gathering for Gardner meeting in Atlanta, Georgia, by Gary Foshee. He went on to say, “The first thing you think is ‘What has Tuesday got to do with it?’ Well, it has everything to do with it.”

I disagree. The day the boy was born is utterly irrelevant. Perhaps it would be best to look at the “accepted” solution from New Scientist before I tell you why it’s hogwash. Its main point is:

The main bone of contention was how to properly interpret the question. The way Foshee meant it is, of all the families with one boy and exactly one other child, what proportion of those families have two boys?
To answer the question you need to first look at all the equally likely combinations of two children it is possible to have: BG, GB, BB or GG. The question states that one child is a boy. So we can eliminate the GG, leaving us with just three options: BG, GB and BB. One out of these three scenarios is BB, so the probability of the two boys is 1/3.

## Rodriguez Robbed

January 17, 2013

Crooked children, yellow chalk
writing on the concrete walk
Their King died
Drinking from a Judas cup
looking down but seeing up
Sweet red wine
‘Cos Papa don’t allow no new ideas here
And now you hear the music
but the words don’t sound too clear

–Sixto Rodríguez, Inner City Blues

I owned four vinyl copies of Cold Fact, Rodríguez’s first album, replacing each one as it became worn out from almost constant play. The CD version now has pride of place in my collection.

We watched the documentary about Rodríguez last night, Searching for Sugar Man. The film explored the possible reasons why Rodríguez was so popular in South Africa, but bombed in his own country—the U.S.A.—and almost everywhere else. In South Africa he was more popular than Elvis Presley (who he?) and the Doors, but in the U.S.A. no one had heard of him. Perhaps, as the film suggests, his subversive lyrics found resonance amongst a repressed population in a police state (this doesn’t explain why he was also successful in Australia); or perhaps his music just ‘went viral’ here—at first it was only available on bootleg casettes before being picked up and marketed by A&M records.

A point only tangentially covered in the film was the issue of royalties. Mr Rodríguez was not aware that his album had gone platinum in South Africa and Australia. He was working in Detroit as a casual labourer on construction sites when he was ‘discovered’ in 1997 by South African journalist Craig Bartholomew Strydom and fan Steven “Sugar” Segerman. It had been thought that he had committed suicide years before.

The question is: who trousered his money? Why did he not receive a penny of the royalties that were due to him? He has been described by film critic Roger Ebert as a “secular saint”, a man who doesn’t seem to care about money at all, but that does not absolve the record company executives who cynically robbed him. Even though he won’t initiate it himself, I hope some law enforcement agency takes the trouble to investigate this crime, and make an example of the perpetrators.

The priest is preaching from a shallow grave
He counts his money, then he paints you saved
Talking to the young folks
Young folks share the same jokes
But they meet in older places