Try to solve the following problem:
A bat and ball cost $1.10.
The bat costs one dollar more than the ball.
How much does the ball cost?
Did you come up with 10¢? You're not alone! Most Harvard students answered 10¢ as well!
The correct answer is 5¢.
Behavioral economist Daniel Kahneman explains why most people get this wrong:
"A number came to your mind. The number, of course, is 10: 10¢. The distinctive mark of this easy puzzle is that it evokes an answer that is intuitive, appealing, and wrong. Do the math, and you will see. If the ball costs 10¢, then the total cost will be $1.20 (10¢ for the ball and $1.10 for the bat), not $1.10. The correct answer is 5¢. It is safe to assume that the intuitive answer also came to the mind of those who ended up with the correct number—they somehow managed to resist the intuition."