A rooster lays an egg on the very top of a pointed barn roof. Which side does the egg roll down?

Neither, roosters do not lay eggs

Brain Teaser Quiz: 10 Tricky Questions That Fool Your Brain

This brain teaser quiz gives you ten tricky questions designed to catch your brain on autopilot, from the pills a doctor gives you to animals on Noah's Ark, smoke from an electric train and a rooster on a roof, plus a look at why psychologist Daniel Kahneman said our fast thinking falls for traps like these. Read slowly before you answer.

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🎯 Daily Trivia Challenge • 🧠 10 Questions • ⏱️ 90 Seconds

Question 1 / 10 Time: 90s

Time
A doctor gives you three pills and tells you to take one every half hour. How long will the pills last?
Stories
How many of each kind of animal did Moses take on the Ark?
Trick questions
A plane crashes exactly on the border between the United States and Canada. Where do they bury the survivors?
Trains
An electric train is heading north, and the wind is blowing toward the west. In which direction does the smoke blow?
Farm animals
A rooster lays an egg on the very top of a pointed barn roof. Which side does the egg roll down?
Families
A man has 10 sons, and each son has one sister. How many children does the man have?
Distances
How far can a dog run into the woods?
Letters
What appears once in a minute, twice in a moment and never in a thousand years?
Clocks
A clock takes 5 seconds to strike six o'clock. How long will it take to strike twelve o'clock?
Birthdays
How many birthdays does the average person have?

Explanations: answer key for all 10 questions

Q1: A doctor gives you three pills and tells you to take one every half hour. How long will the pills last?
Answer: 1 hour
You take the first pill right away, the second after 30 minutes and the third after 60 minutes. So the pills last one hour.
Q2: How many of each kind of animal did Moses take on the Ark?
Answer: None, it was Noah
In the Bible story, Noah built the Ark, not Moses. Many people answer two because the question sounds familiar and they do not notice the wrong name.
Q3: A plane crashes exactly on the border between the United States and Canada. Where do they bury the survivors?
Answer: Nowhere, survivors are alive
Survivors are people who lived, so they are not buried. The detail about the border distracts you from the key word.
Q4: An electric train is heading north, and the wind is blowing toward the west. In which direction does the smoke blow?
Answer: There is no smoke
Electric trains do not burn fuel, so they do not make smoke. The wind and direction are only there to lead you astray.
Q5: A rooster lays an egg on the very top of a pointed barn roof. Which side does the egg roll down?
Answer: Neither, roosters do not lay eggs
Only hens lay eggs. Questions like this test whether you check the starting facts before working on the details.
Q6: A man has 10 sons, and each son has one sister. How many children does the man have?
Answer: 11
All ten sons share the same sister. That makes ten sons and one daughter, or eleven children in total.
Q7: How far can a dog run into the woods?
Answer: Halfway
After the halfway point, the dog is running out of the woods, not into them. This old riddle plays on the word into.
Q8: What appears once in a minute, twice in a moment and never in a thousand years?
Answer: The letter M
Minute has one M, moment has two Ms and a thousand years has none. The question sounds like it is about time, but it is about spelling.
Q9: A clock takes 5 seconds to strike six o'clock. How long will it take to strike twelve o'clock?
Answer: 11 seconds
Six strikes have five gaps between them, so each gap is one second. Twelve strikes have eleven gaps, which take 11 seconds.
Q10: How many birthdays does the average person have?
Answer: One
Everyone has only one birthday, the day they were born, but they celebrate it every year. The question mixes up birthdays and birthday parties.

Brain Teaser Quiz – Why Smart People Get Fooled

Brain teasers are short puzzles that look simple but hide a trick. Some depend on a careful reading of the words, others on a hidden assumption and others on a small detail that changes everything. They are popular in puzzle books, classrooms and job interviews because they reveal whether people slow down and check their thinking.

Psychologist Daniel Kahneman, who won the Nobel Prize in economics in 2002, described two kinds of thinking. System 1 is fast, automatic and intuitive. System 2 is slow, careful and effortful. Brain teasers are designed to trigger a fast System 1 answer that feels right but is wrong. Only by switching to System 2 do we find the real answer.

The question about Moses and the Ark is an example of the Moses illusion. Many people answer two without noticing that Noah, not Moses, built the Ark, because the question fits a familiar story. The pill and clock questions show how easy it is to count the wrong thing: we count pills instead of gaps of time, or strikes instead of pauses between them.

To get better at brain teasers, read each question twice, underline key words and ask whether the starting facts are true. Questions about roosters laying eggs or smoke from electric trains contain a false premise. Spotting it is the whole puzzle.

Brain teasers are also a great social game. Friends can take turns asking them, and even wrong answers lead to laughs and discussion.

If you enjoy this quiz, try our longer brain teasers and lateral thinking puzzles with answers.

What This Quiz Teaches

This quiz is perfect for puzzle fans, families and anyone who loves trick questions.

How brain teasers hide their tricks
Fast and slow thinking, as described by Daniel Kahneman
The Moses illusion
Counting gaps instead of events
How to spot false starting facts
Wordplay in classic teasers

Quick Facts About Brain Teasers

Daniel Kahneman wrote the bestselling book Thinking, Fast and Slow.
The Moses illusion was first studied by psychologists in 1981.
Some tech companies once used brain teasers in job interviews.
Puzzle books have been popular since the 19th century.
Many brain teasers work in only one language because of wordplay.
Solving puzzles with others can make you more willing to take risks with ideas.