"A bat and a ball together cost $1.10. The bat costs $1 more than the ball. How much does the ball cost?
Did you say 10 cents?
More than half of a Princeton University economics class gave the same answer (as did most of my friends), and it is wrong.
The thought process that produced this wrong answer is an example of what Prof Kahneman calls 'System 1 thinking'. It is, he says, 'fast, effortless, associative.' We just impulsively pluck out the most intuitively obvious-sounding answer. We don't stop to deliberate, especially when the question seems trivial."
Click here for the correct answer and the full article in the Business Times.
Here's a visual - without algebra! - how you can figure out the answer quickly, mentally - Thanks to Singapore Math:
http://media.hoover.org/images/ednext20064_38b.gif
Posted by: Aysegul | January 25, 2009 at 11:30 AM
Gosh...I miss this one every time I see it!
Posted by: Joe Begalla | July 18, 2008 at 12:43 PM