Logic Puzzles Quiz: 10 Brain-Bending Questions

This logic puzzles quiz tests careful thinking, with number sequences, the Fibonacci pattern, Shane Frederick's classic bat and ball puzzle, the riddle of Mary's father's daughters, a widget factory, a lily pad pond, a tricky race and a few questions that punish quick guesses. Ten questions, 90 seconds.

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

Question 1 / 10 Time: 90s

Sequences
What number comes next: 2, 4, 8, 16, ...?
Deduction
If all Bloops are Razzies and all Razzies are Lazzies, are all Bloops definitely Lazzies?
Classic
A bat and a ball cost 1.10 dollars in total. The bat costs 1 dollar more than the ball. How much does the ball cost?
Rates
If 5 machines take 5 minutes to make 5 widgets, how long would 100 machines take to make 100 widgets?
Wordplay
Mary's father has five daughters: Nana, Nene, Nini and Nono. What is the fifth daughter's name?
Sequences
What number comes next: 1, 1, 2, 3, 5, 8, ...?
Growth
A patch of lily pads doubles in size every day and covers a pond in 48 days. On which day did it cover half the pond?
Trick
In a race, you overtake the runner in second place. What position are you in now?
Trick
How many times can you subtract 5 from 25?
Calendar
Some months have 31 days and some have 30. How many months have 28 days?

Explanations: answer key for all 10 questions

Q1: What number comes next: 2, 4, 8, 16, ...?
Answer: 32
Each number is double the one before, so the next is 32. Doubling sequences like this are called geometric sequences.
Q2: If all Bloops are Razzies and all Razzies are Lazzies, are all Bloops definitely Lazzies?
Answer: Yes
If every Bloop is inside the Razzie group, and every Razzie is inside the Lazzie group, then every Bloop must be a Lazzie. This kind of reasoning is called a syllogism.
Q3: A bat and a ball cost 1.10 dollars in total. The bat costs 1 dollar more than the ball. How much does the ball cost?
Answer: 5 cents
If the ball cost 10 cents, the bat would cost 1.10 dollars and the total would be 1.20. With a 5-cent ball and a 1.05-dollar bat, the total is 1.10. Psychologist Shane Frederick made this puzzle famous.
Q4: If 5 machines take 5 minutes to make 5 widgets, how long would 100 machines take to make 100 widgets?
Answer: 5 minutes
Each machine makes one widget in 5 minutes. So 100 machines working at the same time make 100 widgets in the same 5 minutes.
Q5: Mary's father has five daughters: Nana, Nene, Nini and Nono. What is the fifth daughter's name?
Answer: Mary
The puzzle tells you at the start: they are Mary's father's daughters, so Mary is the fifth. The pattern of names is designed to distract you.
Q6: What number comes next: 1, 1, 2, 3, 5, 8, ...?
Answer: 13
Each number is the sum of the two before it, so 5 plus 8 makes 13. This is the Fibonacci sequence, named after the Italian mathematician Leonardo of Pisa.
Q7: A patch of lily pads doubles in size every day and covers a pond in 48 days. On which day did it cover half the pond?
Answer: 47
Because it doubles daily, it must have covered half the pond the day before it covered all of it, on day 47. Many people guess 24 by halving the time.
Q8: In a race, you overtake the runner in second place. What position are you in now?
Answer: Second
You take the place of the person you passed, so you are now second. To be first, you would need to pass the leader.
Q9: How many times can you subtract 5 from 25?
Answer: Once
You can only do it once, because after the first subtraction you are subtracting 5 from 20, not from 25.
Q10: Some months have 31 days and some have 30. How many months have 28 days?
Answer: 12
Every month has at least 28 days, so all 12 months have 28 days. February is simply the only month that has no more than 29.

Logic Puzzles Quiz – Think Before You Click

Logic puzzles are designed to catch the part of the brain that answers too quickly. Many of them have an obvious answer that feels right but is wrong, and a correct answer that only appears when you slow down and check your thinking. That is what makes them so satisfying to solve, and so frustrating to get wrong.

Psychologists use puzzles like these to study how people think. The bat and ball problem, made famous by Shane Frederick, is part of a short test of reflective thinking. Most people first answer 10 cents, even very bright students, because the fast, intuitive answer jumps out before careful reasoning has a chance.

Other puzzles test pattern spotting. Number sequences like the doubling pattern and the Fibonacci series appear in math classes, job interviews and IQ tests. The Fibonacci numbers even show up in nature, in the spirals of sunflower seeds and pine cones.

Then there are wordplay puzzles, which hide the answer in plain sight. The question about Mary's father or the months with 28 days is not about math at all but about reading carefully and noticing what is actually being asked.

Take your time with each question; the timer is generous, and the explanations show the reasoning behind every answer.

What This Quiz Teaches

This quiz is great for puzzle fans, students, job seekers preparing for aptitude tests and anyone who likes a mental workout.

How to spot doubling and Fibonacci patterns
How to reason through all-and-some statements
Why the bat and ball puzzle fools so many people
How to think about rates and exponential growth
How wordplay puzzles hide the answer in the question
Why slowing down leads to better answers

Quick Facts About Logic Puzzles

Sudoku became a worldwide craze after British newspapers started printing it in 2004.
The Tower of Hanoi puzzle was invented by French mathematician Édouard Lucas in 1883.
Lewis Carroll, author of Alice's Adventures in Wonderland, also wrote books of logic puzzles.
The Rubik's Cube has more than 43 quintillion possible positions.
The Monty Hall problem is one of the most argued-about probability puzzles.
Regularly solving puzzles is a popular way to keep the mind active.