The Boston Diaries

The ongoing saga of a programmer who doesn't live in Boston, nor does he even like Boston, but yet named his weblog/journal “The Boston Diaries.”

Go figure.

Sunday, July 26, 2015

A plane flying 100 miles per hour and carrying 200 passengers and 5 crew crashes on the border of the United States and Canada. Where do they bury the survivors?

Frederick is perhaps best known for creating the “Cognitive Reflection Test,” a simple measure for whether a person solves a problem “quickly with little conscious deliberation” or through reflective, slow thinking. Kahneman includes the test in his book.

It has three questions:

1) A bat and a ball cost $1.10. The bat costs $1.00 more than the ball. How much does the ball cost? ____cents

2) If it takes five machines five minutes to make five widgets, how long would it take 100 machines to make 100 widgets? ____minutes

3) In a lake, there is a patch of lily pads. Every day, the patch doubles in size. If it takes 48 days for the patch to cover the entire lake, how long would it take for the patch to cover half of the lake? ____days

Via Hacker News, The power of slow thinking - Ideas - The Boston Globe

I will say, I got the first one wrong initially—Oh! It's simple! It's 10¢! But then I thought, Wait! This is a trick! Read that question slowly again … and I was able to puzzle it out. The second one I had to puzzle it out a few times to get it right, but because I program (I work with powers of two all the time) the last one was trivial.

When I tried asking Bunny about these, we had the following conversation:

“I was never good at these type of problems. You know, a train leaves Detroit going at 75 miles per hour, while at the same time, a train leaves Los Angeles going at 80 miles per hour. Where do they meet?”

“Yeah, that's easy.”

“Oh, really?”

“Yeah, they meet head-on.”

“Ha ha ha. Where?

“D'uh! In the United States.”


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