Can You Pass The World’s Shortest IQ Test?

How smart are you, really? The Cognitive Reflection Test (CRT), also known as the world’s shortest IQ test, claims it only takes three questions to tell if you’re a genius.

Developed in 2005 by Princeton psychologist Shane Frederick, the quiz assesses your ability to process information slowly and rationally, rather than jumping to quick conclusions. “In order to succeed in the CRT, you must spend time reflecting on your answer and question your intuitive response,” IFL Science explains.

 Before you get started, we’ll give you a quick hint: the questions might not be as easy as they first seem. A 2003 study found that students attending some of the nation’s most prestigious universities (including Harvard and Yale) failed to get all three of these questions correct; only 17 percent received a perfect score.

Think you have what it takes? Give it a shot! Here are the three questions:

1. A bat and a ball cost $1.10 in total. The bat costs $1 more than the ball. How much does the ball cost?

2. If it takes 5 machines 5 minutes to make 5 widgets, how long would it take 100 machines to make 100 widgets?

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?

Check out the answers below , and best of luck!


The Answers

1. 5 cents – There’s a very good chance you guessed 10 cents.

The answer is actually a little less – a 5 cent ball plus a bat costing $1.05 will set you back $1.10. And, of course, $1.05 is exactly $1 more expensive than 5 cents.

(A Princeton study found that people who responded 10 cents were “significantly” less patient than those who got the right answer.)

2. 5 minutes – Your gut instinct might be to say 100 minutes. Fortunately, it wouldn’t take quite so long. From the question, we can determine it takes exactly 5 minutes for 1 widget machine to make 1 widget. Therefore, it would take 5 minutes to make 100 widgets from 100 widget machines.

3. 47 days – You might have guessed 24 days. It seems intuitive to half the number of days because you’re halving the size of the lilypad patch.

But if the area of the lake covered in lilypads doubles every day, it would only take one day for it to go from being half covered to fully covered.

Take one day away from 48 days and you’re left with 47.






Leave a comment

Your email address will not be published. Required fields are marked *