A collection of challenging quizzes for adults [Difficult]
Feeling the urge to tackle a brain-busting puzzle that seems impossible—“No one could solve this!”—might be a uniquely adult kind of curiosity.
But why do puzzles and riddles that hinge on sudden insight make your heart race? It’s because your brain is seeking that moment of activation.
This time, we’ve handpicked challenging problems for adults that test flexible thinking and ideas unconstrained by common sense.
Don’t overthink them—try looking from a slightly different angle.
The “aha!” moment is surely waiting for you.
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Difficult Logic & Exam-Type Quizzes (For Job Applicants, Examinees, and Geniuses) (1–10)
Apple’s entrance exam
This is a problem that was used in Apple’s employment exam—a famous global company known for products like the Mac and iPhone.
When you think of corporate hiring tests, you might imagine that they mainly assess academic ability, but these problems test not only that, they also gauge creativity and flexible thinking.
While meeting the specified conditions and scenarios, you work your way toward an answer; what matters most is organizing things step by step.
Because these are challenging problems that require combining knowledge with inventive thinking, it’s important to provide appropriate hints if someone finds them too difficult to solve.
Entrance exam questions for highly competitive junior high schools
This is a problem about finding angles in a figure.
For those who aren’t good at math, it might be quite baffling.
It should be solvable with elementary school knowledge, but it’s still quite challenging.
As expected, it’s an entrance exam question from a highly competitive junior high school.
Please try it with the mindset of an elementary school student!
Challenging Math Quiz
Here’s a set of challenging math quizzes designed for adults to enjoy! There are 10 questions in total, including ones that test logical thinking—such as “A bat costs 4,900 yen more than a ball.
How much does the ball cost?”—as well as brain teasers like “Add one line to make the equation correct.” Every quiz will get your brain working and help loosen up a stiff mind.
Many of the problems can be solved without prior math knowledge, so even if math isn’t your strong suit, give them a try!
Mathematics Probability Problem
The prisoner’s paradox, often explained in the context of solving the Monty Hall problem posed in probability theory.
It’s a quiz that asks whether your chances of survival increase if, among three prisoners with only one destined to be spared, you learn in advance who will not be spared.
Although it’s a problem themed around mathematical probability, there’s no need to think in a complicated way.
By following your intuition, you can arrive at the correct answer.
It’s an extremely challenging puzzle packed with the allure of paradoxes—where seemingly sound logic leads to an unsettling conclusion.
An elementary school problem that even University of Tokyo students struggle with
This is a quiz where you look at a drawing or photograph and write what it is in hiragana in the answer boxes.
猫の絵があれば、正しい答えは枠の中に「ねこ」と書くことです。
You might think, “Isn’t that a first-grade question?” Many of you probably feel that way.
However, it’s surprisingly difficult to figure out the answer using just the picture and the number of boxes.
Some problems clearly don’t match the number of boxes with the answer, and some pictures or photos are hard to identify at first glance.
Give it a try!
What is Lisa’s score?
This is an arithmetic problem from a junior high school entrance exam.
Look at the table and determine the score that goes in the “?”.
The key to reaching the answer is finding where the pattern lies and what kind of rule is being used.
It’s intended for elementary school students, but it’s a math problem that can make even adults think quite hard.
Apples on a deserted island
It’s a tough problem that tests your calculation skills: How many apples were there to begin with? One person eats one third of the apples, the next person eats one third of the remaining apples, then the next person eats another third, and so on.
Just writing it out like this is complicated.
If you’re confident in your arithmetic, give it a try.