Do you think you’re a logical person? If the answer to this question is “Yes”, then try this simple test. We should, however, let you know that 90% of people who try to solve this test come to the wrong conclusion. If you think you’re ready, then let’s start:
Below are four cards. Each card is numbered on one side and has a color on the other side. Your objective is to prove the following statement:
“If a card shows an even number on one face, then its opposite face is blue.”
In order to prove this statement, what is the minimal number of cards you’ll have to flip, and which ones? Take your time to think of the answer, and once you think you're sure, scroll down to see if you're correct.
As the table below shows, you have 16 different options to choose from.
So, you think you've come to the right conclusion? Scroll down to find out.
Answer
The correct answer is: 2 cards - The card with the number 8 digit, and the green card.
The majority of people assume you need to flip number 8 and the blue card, because these are the two cards the question refers to. However, a truly logical thinker would realize that this is incorrect.
The statement in question tells you that when a card has an even number on one face, the other face must be blue.
Therefore, first you need to prove that the back of number 8 is blue – that’s easy enough.
There’s no need to check the blue card, because the statement doesn’t discuss what’s on the other side of blue cards, but rather what’s on the other side of even cards.
Once you check the green card, you can ascertain whether it’s an odd or even number. If the number’s even, then the statement is false.
Only MENSA Members Will Be Able to Pass This Quiz...
Think you're king of the hill when it comes to logical puzzles? Let's see how smart you really are!
Challenge! Can You Solve These 7 Tricky Riddles?
These riddles will challenge your mental sharpness and will definitely keep you on your toes.
QUIZ: Can You Guess What These Fancy English Words Mean?
It's time to find out just how fancy your range of vocabulary really is! Good luck...
Do You Have Common Sense? Take Our Test!
Common sense is the intelligence that everyone OUGHT to have and it isn't as common as you might think. Take our test to see if you have more than your fair share, or not!
This Colorful Test Will Help You Improve Your Vision
This visual test isn't only fun, but it also stimulates your eye muscles and exercises the visual part of your brain at the same time.
Quiz: Your Perception Says a Lot About Your Personality!
The way we perceive things says a lot about our personality. Take this test to find out how your eyes can reveal your innermost personality traits.
Can You Count All the Tigers Hiding in This Photo?
It might look like there are but 4 tigers in this image, but there are a lot more. How many can you find? Click on the image to see how many there are.
Challenge: Can You Spot the Hiding Animal?
Sometimes, when we're not all that attentive, we can easily miss the wonderful things hidden in nature. Find out if you can spot the animals in the pictures.
PUZZLE: Can You Find all the Hidden Words in the Picture?
Picture puzzle with six hidden words
Challenge: Can You Crack These 10 Riddles?
Can you crack these 10 challenging riddles?
Quick Test: Choose an Eye and Discover More About Yourself
The eyes are a window to the soul - choose yours and see what it says about you.
These 8 Fun Riddles Will Test You to the Max!
Do you think you're a riddle brainbox? If so, give these 8 tricky riddles a try!
Have a Go at Solving These Tricky Murder Riddles
Halloween is just around the corner, so to get you in the mood, we've given you 11 murder riddles to solve. Do you think you have what it takes? Find out now.
10 Fun Visual Brain Teasers You Will Want To Share
Brains need exercise just as much as muscles do. Challenge yourself with these 10 fun observation tests.
Challenge: Can You Solve the 4 Square Riddle?
To solve this riddle, you must forget what you think you know...
You Don't Genius to Solve This, But it Surely Helps!
This isn't just another easy test - can you crack it?
Challenge: Can You Solve These 10 Tricky Riddles?
These ten challenging riddles will leave you scratching your head.
Can You Guess These Ancient Riddles?
Can you solve these riddles thousands of years old?
Challenge: Are You Clever Enough For This Riddle?
A simple riddle that will drive you crazy!
Riddle Me This: Test Your Logic by Solving Riddles!
These tricky riddles are not only fun but also will test your brain - give them a go, and see if you can solve them all!
Can Spot the Difference in These Brain-teasers?
Are you good at brain-teasers? If you think so, then you should really take on these 8 awesome brain-teasing images by Gergely Dudás.
Only a Few People Can See What's Hiding in This Image
What hides behind this red circle? Only a few can tell...
These Riddles Have Simple Answers, But Can You Find Them?
These riddles all have very simple answers, but may not be as easy to solve as they appear.
Test Your Mental Sharpness With These Brainteasers
See if you can figure out all of these brainteasers without peeking at the answers.
Let's Play a Game: Spot the Doubled Animal!
Are you ready for a quick game of wits? Let's see how fast you can locate the animals that appear twice in this game!
Can You Crack These Challenging Animal Riddles?
How well do you know the animal world? Can you crack our riddles and guess the animal in this collection of animal riddles?
Can You Solve These 10 Tricky Riddles? Give It a Go!
If you love to test yourself with challenging riddles, then give these 10 a go!
Challenge: Think You Can Crack These 10 Riddles?
These challenging riddles ask one simple question: Are you a riddler?
Are You One of the 3% Who Can Really See This Image?
Can you see this image? Are you one of the lucky few?
Challenge: Can You Find the 6 Hidden Words in this Drawing?
Hidden in the image are six words that have been concealed. Only about 33% of adults will be able to find them all, making it one tough puzzle to complete.
Can You Solve These Tricky Little Riddles?
While some of us are good at solving riddles, others are just not. How do you do? Here are 9 tricky little riddles to put your brains to the test.
Challenge! Can You Solve These 7 Tricky Riddles?
These riddles will challenge your mental sharpness and will definitely keep you on your toes.
What You See In These Images Will Tell You About Yourself
Many personality tests rely on your choices to determine your personality, but this optical illusion test will work entirely on your subconscious...
10 Challenging Riddles to Test Your Thinking Skills
These brain-teasing riddles will definitely test your lateral thinking skills. So, get those cogs working and try to answer all 10!
Challenge: Think You Can You Crack These 5 Math Riddles?
Test your math knowledge with these 5 fun math riddles.
Massive Riddle Collection: 120 Tricky Riddles to Test You!
Here is our enormous collection of 120 tricky riddles with answers that will definitely make you put your thinking cap on!
Are You Part of the 5% Who Can Solve These Logic Puzzles?
These puzzles will tease your brain like never before. If you manage to solve them, you'll be in an elite group - only 5% of people are capable of doing so.
Can You Correctly See What's Hidden in These Images?
Can you see what's really hidden in these images? Click on each one to find the answer.
Is Your Mind as Sharp as a Knife? Try These Brain Teasers!
These addictive brain teasers will really get the cogs in your head turning!
Can You Solve These 16 Perplexing Riddles?
There's no better brain workout that trying your hand at a few riddles.
Can You Solve These 8 "Mind Blowing" Riddles?
These riddles will show you that brain-teasing isn't just for kids. Do you have what it takes to solve these 8? Give them a go to find out!
Spot the Differences & Test Your Observational Skills!
Only the most observant of people can find all the differences between these images. Are you one of that select band of clever clogs?
How Many of These Clever Riddles Can You Answer?
How many of these riddles can you guess?
Only 2% of People Can Solve This Riddle! Can You?
According to the great Albert Einstein, only 2% of the world's population can solve this riddle by themselves. Are you one of them?