**Via Scoopinon Article**

**A simple logic question that most Harvard students get wrong**

**“**HARVARD STUDENTS GET near-perfect SAT scores (US college admission tests). These are smart, smart kids. So they shouldn’t have trouble with a simple logic question, right?

Try the following puzzle:

*A bat and ball cost $1.10. **The bat costs one dollar more than the ball. **How much does the ball cost?*

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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.

… This excerpt comes from Kahneman’s 2011 book, Thinking, Fast And Slow, which posits that we have an intuitive mental system and a logical mental system, and we often use the wrong one at the wrong time.”