If you’ve always wanted to test your intelligence, but couldn’t be bothered by a long test, this may be the perfect solution.

The world’s shortest IQ test consists of just three math questions and shouldn’t take too long.

But beware, the questions seem easy, but even Harvard and Yale students found them difficult.

Of all those who participated, only 17 percent managed to get three out of three marks, for an 83 percent failure rate.

Called the Cognitive Thinking Test, the quiz is nothing new. It was originally part of a research paper published in 2005 by MIT Professor Shane Frederick. It recently resurfaced online.

As part of his research, Professor Frederick took the test to over 3,000 participants from a variety of educational backgrounds – and even those who attend America’s top universities struggled.

Speaking about the test, Prof Frederick said: “The three elements of CRT are ‘easy’ in the sense that their solution is easily understood when explained, but achieving the correct answer often requires removing a wrong answer which occurs “impulsively”. ‘ in mind.”

### **Here is an overview of the 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 five machines five minutes to create five widgets, how long would it take 100 machines to create 100 widgets?

3. In a lake, there is a square of water lilies. 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?

### These are the three most common answers – but they are actually **Incorrect.**

1.10 cents

2.100 minutes

3. 24 days

Professor Frederick adds: “Anyone who thinks about it for a moment would agree that the difference between $ 1 and 10 cents is only 90 cents, not $ 1 as the problem states.

“In this case, detecting this error is tantamount to fixing the problem, because almost everyone who does not answer” ten cents “does, in fact, give the correct answer.”

### **The correct answers are:**

1.5 cents

25 minutes

3. 47 days

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Still puzzled? Fortunately, Presh Talwalkar, author of The Hoy of Game Theory: An Introduction to Strategic Thinking, explained how to find the right answers on his blog, Pay attention to your decisions.

1. Suppose the ball costs X. Then the bat costs $ 1 more, so it’s X + 1. So we have bat + ball = X + (X + 1) = 1.1 because together, they cost $ 1.10. This means 2X + 1 = 1.1, then 2X = 0.1, so X = 0.05. This means the ball costs 5 cents and the bat costs $ 1.05

2. If it takes 5 minutes for 5 machines to create 5 widgets, then it takes 5 minutes for 1 machine to create 1 widget (each machine makes a widget in 5 minutes). If we have 100 machines working together, each one can create a widget in 5 minutes. So there will be 100 widgets in 5 minutes.

3. Each day the patch doubles in size. So every BACKWARDS day means the patch size decreases by half. So, on day 47, the lake is half full.

*How did you do? Let us know in the comments below.*