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Can You Make 24 From 3, 3, 8, 8? It’s Surprisingly Hard!

This problem is tougher than it looks! Make 24 from the numbers 3, 3, 8, 8. You can only use the operations + – × ÷ (). You have to use all four numbers (the digit 3 two times and the digit 8 two times). There are no tricks here! Can you figure it out? … Continue reading Can You Make 24 From 3, 3, 8, 8? It’s Surprisingly Hard! Read more ›

Can You Solve A HARD Korean Test Question? Cone-Shaped Mountain Puzzle

I received an email suggesting today’s puzzle (email and problem slightly edited for presentation purposes): I am a high school student in Korea. I greatly enjoy watching your YouTube channel. I am writing to share with you a math problem from the Korean SAT, the CSAT (College Scholastic Ability Test). This problem is from the … Continue reading Can You Solve A HARD Korean Test Question? Cone-Shaped Mountain Puzzle Read more ›

The Math Problem That Stumped Piers Morgan – Lady Karren Brady’s Twitter Challenge

In January 2018, Lady Karren Brady posted a maths puzzle on Twitter, challenging people to solve it in 3 minutes. After she posted the correct answer, Piers Morgan claimed it was incorrect. As it turns out, Piers Morgan was the one who was wrong. He verified the correct answer on his calculator, and then he … Continue reading The Math Problem That Stumped Piers Morgan – Lady Karren Brady’s Twitter Challenge Read more ›

Can You Solve The Faucet Drain Puzzle? Math Exam Question From Hungary

Today’s puzzle is from this email (slightly edited) Hi, I got this problem in an exam in Hungary for 15 year olds. At first I could not figure it out. I got so frustrated that I was thinking about it all day. When I finally got the answer I was soo happy. Now the problem: … Continue reading Can You Solve The Faucet Drain Puzzle? Math Exam Question From Hungary Read more ›

Can You Solve Professor Henk Tijms’ Birthday Candles Puzzle?

(If you buy from the book links in this post I may receive a commission for sales. This has no effect on the price for you.) A few years ago I read a great introduction to probability titled Understanding Probability by Professor Henk Tijms. This was not for school or for work. I just read … Continue reading Can You Solve Professor Henk Tijms’ Birthday Candles Puzzle? Read more ›

“Prove” 3 = 0. Can You Spot The Mistake?

Here’s a portion of an email I received: Hi, I am Lucas from Brazil and I love your videos. Here is a problem from a book with math problems that I could not solve and the book doesn’t say the answer, just said “This one we leave to the students!” I translated the problem for … Continue reading “Prove” 3 = 0. Can You Spot The Mistake? Read more ›

Can You Solve A 5th Grade Math Problem From China? (To Identify Talented Students)

Thanks to Bill from New York for today’s problem! Here’s a slightly edited version of the email he sent me: Hi Presh: I got this problem from a Chinese math teacher. It was used to identify gifted kids for competition. ABCD is a parallelogram. In the diagram (see below), the areas of yellow regions are … Continue reading Can You Solve A 5th Grade Math Problem From China? (To Identify Talented Students) Read more ›

Can You Solve The Roll, Roll, Roll A Dice Game Puzzle?

Thanks to James M. for this suggestion! You play a dice rolling game where you can win money. You roll a fair six-sided dice. You can stop and earn the value of the roll (in dollars), or you can roll again. If you roll again, the same rules apply: you can stop and earn the … Continue reading Can You Solve The Roll, Roll, Roll A Dice Game Puzzle? Read more ›

How Many Triangles Do You See? A Challenging Puzzle

This is a puzzle I saw from the St. Louis Science Center Twitter account. I admit that I could not solve it! This is a good old-fashioned test of observational skills. Can you count all of the triangles? Give it a try, and then watch the video for a solution. How Many Triangles Do You … Continue reading How Many Triangles Do You See? A Challenging Puzzle Read more ›

Can You Solve The Seemingly Impossible Cyclist And Motorcycles Riddle?

I received this puzzle by email, which I have edited for presentation. I follow your YouTube channel and you are great. I have created a puzzle you might like. A cyclist ascends a long climb at a constant speed of 18 kilometers per hour (km/h). A motorcycle rally starts 1 minute after the cyclist. Every … Continue reading Can You Solve The Seemingly Impossible Cyclist And Motorcycles Riddle? Read more ›

How Many Holes Does A Straw Have? The Correct Answer Explained Mathematically

How many holes does a straw have? This question has generated a lot of debate online. Recently BuzzFeed made a video that already has over 450,000 views. It’s amazing to see topology go viral like this! Topology is a branch of mathematics dealing with the study of shapes and spaces. And it was an important … Continue reading How Many Holes Does A Straw Have? The Correct Answer Explained Mathematically Read more ›

Presidents’ Day Special: Math Homework From George Washington And Abraham Lincoln

For Presidents’ Day, we celebrate the birthdays of George Washington (February 22, 1732) and Abraham Lincoln (February 12, 1809). Both men understood the value of mathematics. Abraham Lincoln studied Euclid’s Elements to understand logical proof (details here). And here’s a quote from George Washington. “Without arithmetic, the common affairs of life are not to be … Continue reading Presidents’ Day Special: Math Homework From George Washington And Abraham Lincoln Read more ›

Another Singapore Birthday Math Problem Stumps The Internet

This is not about the famous Cheryl’s birthday problem. According to Mothership, a Singapore math question on students’ birthday months has everyone stumped. Again. What is the question? It looks easy enough. “There are 37 students in a class. How many students, at the least, are born in the same month?” Okay, so I know … Continue reading Another Singapore Birthday Math Problem Stumps The Internet Read more ›

Can You Solve Abraham Lincoln’s Math Homework?

In honor of Abraham Lincoln’s birthday on February 12, I want to share a fascinating but lesser known story. While Lincoln was studying law, he frequently came upon the word “demonstrate.” He wondered what “demonstrate” meant compared to any other proof. So he looked it up in Webster’s Dictionary and found that demonstrate meant a … Continue reading Can You Solve Abraham Lincoln’s Math Homework? Read more ›

The REAL Answer To The Viral Chinese Math Problem “How Old Is The Captain?” Stumping The Internet

A 5th grade math exam in China had the following question (translated to English): “If a ship had 26 sheep and 10 goats onboard, how old is the ship’s captain?” The question baffled students and parents, garnering headlines around the world. Even I covered the problem, but there is more to the story than anyone … Continue reading The REAL Answer To The Viral Chinese Math Problem “How Old Is The Captain?” Stumping The Internet Read more ›