If the tests to measure intelligence bore you (and, let’s face it, they are often long and pedantic so the temptation to abandon them comes soon), these three quick questions I’m the one for you. It is, in fact, the quiz that can rightfully be considered the fastest in the world but, be careful: it should not be underestimated for this reason! The test was developed by Shane Frederick, a professor at MIT (Yale University), in 2005 with the aim of measuring not the IQ but the cognitive reflection, or the ability to reflect.
Therefore, it is not a question of a quiz that returns a data on intelligence, that is, those who make mistakes are not necessarily less intelligent than those who answer correctly. The three questions, in fact, indicate only the degree of instinct with which you respond, with the relative risk of making mistakes. First published in the ‘Journal of Economic Perrspectives’, therefore, the test tells us whether we are impulsive or reflective people. Are you ready? Here are the questions (at the end of the article you will find the relative solutions).
- The first question is about a baseball bat and a ball: these cost, on the whole, 1.10 dollars. Assuming the bat costs a dollar more than the ball, how much does the ball cost?
- The second has to do with a automatic machine: If 5 machines take 5 minutes to complete 5 pieces, how long does 100 machines take to complete 100 pieces?
- Finally, the third request speaks of a lake with water lilies: every day, the water lilies of the lake double in size compared to the previous day. If in 48 days they cover the entire surface of the lake, how long does it take to cover half of it?
Take your time.
So, let’s get to the answers.
- The correct answer is 5 cents. Many respond, instinctively, that the ball costs 10 cents but, in this case, the club alone should cost € 1.10, which is the total price (club + ball). Instead, the bat alone costs 1.05 cents which, added to the 5 cents of the ball, gives 1.10 euros.
- The correct answer is 5 minutes. The most impulsive responds, on the other hand, 100 minutes but in this way the time for each machine would also increase, which instead remains fixed. In other words, every 5 minutes 1 machine produces 1 piece, so every 5 minutes 100 machines produce 100 pieces.
- The correct answer is 47 days. Since in a single day the water lily extension doubles and it takes 48 days for the entire surface, the day before the water lilies will be exactly halfway. The response of the impulsive? 24, but it would mean that on the 25th day the water lilies did not cover the whole lake.
Out of a sample of 3428 respondents, only 17% of people answered all the questions correctly (source greenme).
