Just 20% of Participants Successfully Tackle MIT-Endorsed Three-Question IQ Challenge

Remarkably concise, the world’s shortest IQ assessment consists of just three questions, yet it effectively determines if you possess greater intelligence than 80% of the population.

Known as the Cognitive Reflection Test (CRT), this assessment has been around since 2005. However, its popularity has surged on social media following a viral TikTok video explaining the questions, amassing 14 million views.

Psychologist Shane Frederick, who is currently affiliated with Yale School of Management, developed the test to assess the likelihood of individuals making common cognitive errors in judgment and decision-making.

In the years since its inception, numerous studies involving thousands of college students have revealed that fewer than 20% can answer all three questions correctly.

The questions focus on calculating the price of a bat and ball, determining how long a machine takes to produce widgets, and evaluating a scenario involving lily pads covering a lake. While they may seem straightforward at first glance, these questions are designed to be deceptively challenging.

The first question is: A bat and a ball together cost $1.10. The bat costs $1.00 more than the ball. How much does the ball cost?

The second question is: If it takes five machines five minutes to make five widgets, how long would it take 100 machines to make 100 widgets?

Finally, the third question is: 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?

Studies have calculated that getting all three questions on the Cognitive Reflection Test correct suggests you’re smarter than over 80 percent of the population (Stock Image)

Question 1: A bat and a ball together cost $1.10. The bat costs $1.00 more than the ball. How much does the ball cost?

The CRT is tricky because each question has an obvious ‘intuitive’ answer that pops into your head right away; however, that first guess is wrong.

The correct answer requires slowing down and reasoning out the solution, relying on the test taker’s ability to be reflective and thoughtful.

For the question about the bat and the ball costing $1.10 together, and the bat costing $1.00 more, those taking the test commonly answer that the ball costs $0.10, but they’re wrong.

The correct answer to question one is: the ball costs $0.05. That makes the bat cost $1.05, exactly one dollar more than the ball, and makes their combined price add up to $1.10.

Those who get this first question wrong often jump at the basic math of $1.00 plus 10cents equals $1.10, but Frederick noted that this ignores the part of the question which states that the bat is exactly $1.00 more than the ball.

Frederick’s original study at the Massachusetts Institute of Technology gave the IQ test to 3,428 people who were mostly students at MIT, Princeton, and Harvard at the time.

That experiment, published in the Journal of Economic Perspectives, revealed only 17 percent could get all three questions right, meaning these individuals excelled at cognitive reflection and reasoning, key measures of intelligence that tests like the SATs also gauge.

One TikTok video discussing these questions, originally created in 2005, recently received more than 14million views

Question 2: If it takes five machines five minutes to make five widgets, how long would it take 100 machines to make 100 widgets?

For the question asking how long it would take 100 machines to build 100 widgets, the vast majority incorrectly think the answer is 100 minutes.

The correct answer is just five minutes. That’s because each machine makes one widget in five minutes, so 100 machines working together would make 100 widgets in the same amount of time.

Since the first part of the question explains that five machines build five widgets in five minutes, the test taker can disregard any information about the number of machines since the time remains constant.

Question 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?

When test takers reach the final question, asking how long it would take the lily pads to cover half the lake, the common answer given is 24 days, but that would be way off.

The correct answer is 47 days. Since the lily pads double in size every day, and the lake is completely covered after 48 days, that means the lake would double from 50 percent coverage to 100 percent coverage just one day later.

For those who got the answer wrong, researchers have explained that halving the time might seem logical, but it doesn’t account for exponential growth.

The CRT acts in a similar way to the SATs, testing the participant’s ability to avoid common mistakes in thinking and decision-making (Stock Image)

A 2011 study by researchers in the US and Canada found the CRT stumped even more people than in Frederick’s original experiment.

The study in Memory & Cognition, which tested 346 college freshmen, found that only 6.6 percent were able to get all three questions right.

However, Professor Mohammad Noori claimed in the journal Judgment and Decision Making in 2016 that 41.3 percent of 395 Iranian university students correctly answered all three questions.

While the results may vary depending on who’s being tested, the debate on social media continues to rage on, with many still convinced they have the right answers.

‘Lmao everyone thinks it’s 5 minutes,’ one person posted about the second question on a viral TikTok.

‘It is tho,’ someone quickly replied.

‘The bat costs 1.50, the ball costs .50. You get them both for 1.10,’ another social media user posted on a thread viewed over 5.5million times.

‘The math ain’t mathing,’ another user said mockingly.