World's shortest IQ test has 3 questions but 80% failure rate

If you've ever wanted to test your intelligence, but couldn't be bothered to sit a lengthy test, this may be the perfect solution.

The world's shortest IQ test is made up of just three maths questions and shouldn't take too long to complete.

The questions sound easy but even students at Harvard and Yale found them tough.

Of all those who took part only 17 per cent managed to score three out of three - that's an 83 per cent failure rate, Cornwalllive.com reports.

Called the Cognitive Reflection Test, the quiz isn't new. It was originally part of a research paper published in 2005 by MIT professor Shane Frederick. It has recently resurfaced online.

As part of his research, Professor Frederick had more than 3,000 participants from a range of educational backgrounds complete the test - and even those attending top American universities struggled.

Speaking about the test, Professor Frederick, said: "The three items on the CRT are 'easy' in the sense that their solution is easily understood when explained, yet reaching the correct answer often requires the suppression of an erroneous answer that springs 'impulsively' to mind."