The world of IQ testing is filled with complex questions and puzzles designed to challenge your cognitive abilities. However, there exists a fascinatingly short IQ test that consists of just three questions. While it may seem simple at first glance, this test is known to trip up even the most intelligent individuals.
- A bat and a ball cost $1.10 in total, the bat costs $1 more than the ball. How much does the ball cost?
- If it takes five machines five minutes to make five widgets, how long would it take 100 machines to make 100 widgets?
- In a lake there’s 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?
Take your time, see if you can figure out the answers to the questions, then scroll down and see if you were correct.
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Think you got them? Let’s find out!
The first question presents a seemingly straightforward math problem: A bat and a ball cost $1.10 in total. The bat costs $1 more than the ball. How much does the ball cost? Many people’s instinctive response is 10 cents. However, that would mean the bat costs $1.10, making the total $1.20. The correct answer is that the ball costs 5 cents and the bat, costing $1 more, is $1.05.
The second question asks: If it takes five machines five minutes to make five widgets, how long would it take 100 machines to make 100 widgets? The intuitive answer might be 100 minutes, but that’s not right. Since one machine can produce one widget in five minutes, 100 machines can do the same in five minutes. Therefore, the correct answer is five minutes.
The final question revolves around exponential growth: In a lake, there’s 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? The quick answer seems to be 24 days, but remember the patch doubles daily. So, if the lake is fully covered on the 48th day, it must have been half-covered the previous day, thus the correct answer is 47 days.
These questions are part of a cognitive reflection test developed by MIT professor Shane Frederick. They are designed to assess your ability to ignore your intuitive response and reflect on the problem before answering. Interestingly, despite their simplicity, these questions often stump respondents. Only approximately 17% of people get all three questions right, according to Frederick’s research.
So, how did you do?