HOW DO YOU FIGHT A HORSE SIZE DUCK?
by William Poundstone (Oneworld £16.99, 320pp)
Jack looks at Ann. Ann looks at George. Jack is married, but George is not. Does a married person look at an unmarried person?
If, like me and pretty much everyone who hears this question, you answered, “It depends if Ann is married,” then you need to read this book. Especially if you are about to go for a job interview.
Many companies today use such puzzles as part of their recruiting process. William Poundstone has collected some of the most common examples, with the aim of helping prospective employees get their brains working the right way. He’s also thrown in some “history of the interview” material and created an entertaining book for all of us to enjoy.
William Poundstone has written an intriguing book on the most frequently asked questions in job interviews. Pictured: Albert Einstein
Thomas Edison, for example, wrote a list of 146 ‘extremely simple’ questions to assess who wanted to work for him. Among them was: ‘What is the speed of sound?’ A newspaper tested Albert Einstein on this. The scientist replied that ‘he could not say out of hand. . . He had no such information in mind, but it was readily available in textbooks.” I think this says a lot about so-called ‘important’ information.
Equally refreshing is Elon Musk, with his skepticism about academic qualifications. “You don’t need a college degree at all,” he says, “or even high school” to get a job at his companies Tesla and SpaceX.
Instead, Musk is interested in your ability to think and reason. His favorite interview question, which he always asked all employees (even janitors) was, “You are on the surface of the earth. You walk a mile to the south, a mile to the west and a mile to the north. You end exactly where you started. Where are you?’
If an interviewee answered “the North Pole,” Musk would say they were right, but then ask “Where else could it be?” As the book shows, there are an infinite number of points, all just over a mile north of the South Pole.
You walk south, then west “all around the world” in a one-mile circle centered on the pole, then north to where you started. (This is hard to explain – the illustrations in the book help.)
Some modern companies filter applicants by making them take online tests, where part of the score is for response times. It’s all a long way from 1941, when Bletchley Park recruited codebreakers by secretly contacting the winners of the Daily Telegraph’s cryptic crossword competition.
Some questions are a matter of guessing. For example, “How much does the Empire State Building weigh?” This is just a matter of guessing the size, how much of it is made of which materials and so on. You will be judged on how well you can reason as well as on accuracy. For what it’s worth, the building’s current owners say it weighs 365,000 tons.
HOW DO YOU FIGHT A HORSE SIZE DUCK? by William Poundstone (Oneworld £16.99, 320pp)
Then there are the basic math questions, which can often be misleading. If you do the first lap of a circuit at an average speed of 60 miles per hour, how fast should you go on your second lap to average 120 miles per hour in total? The answer is that it is impossible.
Even if you were driving at a million miles per hour, you could never get your average to 120. That’s because you took all the allotted time in the first round.
An easier way to present the same principle is, “If I can eat an average of one donut a day in a week, and I eat seven donuts on the first day, how many can I get off?”
Probability plays a big part, and again it can trip you up. ‘Every day you go to the metro station and take the first train that arrives. The trains to the upper city and the inner city run equally often, but 90 percent of the time you will end up taking a train to the upper city. Why would this be?’ The key here is not only the frequency of the trains, but also the times they arrive.
Suppose the trains in the upper city arrive at 5.10, 5.20, 5.30 and so on, while the trains in the center arrive at 5.11, 5.21, 5.31 … There is a 90 percent chance that you will arrive between, say, 5.11 and 5.20, and therefore the 5.20 uptown train, but only a 10 percent chance that you will arrive between 5.20 and 5.21 on the 5.21 downtown train.
Poundstone also tackles the “odd” questions, such as “You’re a new crayon in the box – what color would you be?” He says there is no right answer, but in my opinion there is, and it’s ‘p*** off’. Overall though, the book is very informative and funny.
And that ‘married/unmarried’ question? The answer is that whatever Ann’s status, a married person looks at an unmarried person. When Ann is married, it is she who watches George. If she isn’t, it’s Jack watching her.