brown colored wooden letters in the background, and 'IQ' in the foreground. Intelligence and IQ concept
Leah Berenson
Leah Berenson
November 6, 2023 ·  5 min read

World’s Shortest IQ Test Only has Three Questions, but 80% Fail

This artcle was originally published on August 22, 2023 and has since been updated.

Intelligence is measured in a variety of ways, including taking an IQ Test. Apparently, the world’s shortest IQ test is only 3 questions and a large percentage of the population have been unable to answer correctly.

In 2005, a professor named Shane Frederick, devised a test with only 3 questions. The IQ Test quickly went viral but was Initially administered to 3,000 participants. The Yale School of Management professor was blown away to find that an astonishing low number of those first participants answered 3 out of 3 questions correctly, only 17 percent.

It has been nearly 20 since the original IQ Test. Nevertheless, it resurfaces every few years or so, once again becoming popular online.

IQ Test Stumping the Internet

Question #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?

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

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?

Although not the correct answers, the most common responses from those who participated in the IQ Test and answered incorrectly were 10 cents, 100 minutes and 24 days. However, the correct answers are 5 cents, 5 minutes, and 47 days.

“Anyone who reflects upon it for even a moment would recognize that the difference between $1 and 10 cents is only 90 cents, not $1 as the problem stipulates.” Frederick explained. “In this case, catching that error is tantamount to solving the problem, since nearly everyone who does not respond ’10 cents’ does, in fact give the correct response.”

IQ Test Answers Explained

So many people have been baffled by the 3 question IQ Test that Presh Talwalker “attempted” to simplify Frederick’s explanation. Presh Talwalker has 3 million subscribers on YouTube and studied both Mathematics and Economics at Standford. He’s known for posting an array of videos ranging from math problems and brain teasers to interview questions. “Say the ball costs X. Then the bat costs $1 more, so it is 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.” He said in his blog, Mind Your Decisions.

Question #2, he explained, “If it takes 5 machines 5 minutes to make 5 widgets, then it takes 1 machine 5 minutes to make 1 widget (each machine is making a widget in 5 minutes). If we have 100 machines working together, then each can make a widget in 5 minutes. So there will be 100 widgets in 5 minutes.

Lastly, question #3 was explained in the following manner. “Every day FORWARD the patch doubles in size. So, every day BACKWARDS means the patch halves in size. So, on day 47 the lake is half full.

Although both explanations are in some way confusing and in others, clarifying, the most important elements of successfully taking an IQ Test are simply slowing down to think carefully about the answers. Or predict the next sequence based on a pattern. The second most important part of successfully taking an IQ Test is to listen diligently to the words in the riddle. Most often, riddles are worded based on some kind of technicality, that can easily be picked up on.

Worldwide Scores

The global average for an IQ Score is around 100, with some places like Hong Kong averaging 108. Meanwhile, in other places in the world like Botswana and Malawi are much lower ranging between 60-70. Sadly, IQ tests have long been part of the inspiration behind racial tensions. It was taught that things like genetics or gender played a role. However, we now know that isn’t the case and sometimes low IQ Test scores reflect a lack of available resources and support. Healthline also discloses some other factors that help determine an IQ Test score. Including but not limited to a highly nutritional, or not, diet. Environmental factors such as pollutants in drinking water. Lastly, consistent, quality education and access to music from an early age.

Some people are boastful or obsessed with their own, or other people’s achievements regarding a high IQ. Therefore, they’re adamant that an IQ Test is necessary for measuring intelligence. In that regard, Healthline explains that IQ actually stands for “intelligence quotient”. So, within its own name an IQ Test does measure intelligence. However, it’s not the only measurement for intelligence.

It’s important to note that not everyone is good at taking tests. Some people panic under pressure. They put so much pressure on themselves that they blank on everything they know or have studied. In contrast, intelligence can be measured through more than just taking an IQ Test.

Other Measurements of Intelligence

There are 8 types of intelligence each can be broken down into a category, but each consists of varying attributes like compassion, self- awareness, creativity, or mathematical understanding. Additionally, intelligence can be measured based upon actions, how someone treat others, and how they’ve handled or overcome certain circumstances in life.

Although an IQ Test isn’t the only way to measure intelligence, the people who’ve worked hard or have the natural brain power for a high score should be celebrated. For example, a 3-year-old in the UK and a 3-year-old in the US both broke records after being accepted into the MENSA program.

Meanwhile, some of the smartest children in history include Wolfgang Amadeus Mozart, William Rowan Hamilton, and Michael Kearney. Female geniuses include Shakuntala Devi, Saffron Pledger, and Sufiah Yusof.

Measuring intelligence with an IQ Test is just one of a few ways to do so. However, intelligence can also shine bright with creativity and love. Or change the world with problem-solving and engineering. Either way, when children, and adults, are nurtured and encouraged, they’ve been known to perform better and forge advantageous paths for the rest of society.

Keep Reading: Separated Identical Twins Raised In The US And Korea Have Massive IQ Difference


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  2. The three-year-old with an IQ of 171.BBC. August 16, 2018
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  4. World’s shortest IQ test only has three questions but 80% fail it.Lad Bible Emily Brown. August 18, 2023.
  5. 16 of the smartest children in History.” Insider. Vivian Giang. June 15, 2011.
  6. What Is the Average IQ?Healthline. Timothy Lang. April 11, 2015.
  7. Can You Pass the World’s Shortest IQ Test? Less Than 20% of People Can.Reader’s Digest. Brooke Nelson. October 14, 2022.