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


Hey, this is Presh Talwalkar. Here’s a math problem that’s stumping the Internet right now. This question was asked to 5th graders in China: ”If a ship had 26 sheep and 10 goats aboard, how old is the ship’s captain?” This problem has gotten a lot of media coverage, and I even covered it in a previous video, But we all missed the real story. This problem was actually devised by French researchers nearly 40 years ago! And it does teach a valuable lesson about math class. So in this video, I’m gonna go over the REAL story, that no media outlet has covered so far. Before I get to that, I want to quickly go over the media coverage, and what some possible answers have been proposed. So this problem really got coverage around the world. From the South China Morning Post, from RT, from the BBC, from the Washington Post and even in Newsweek. The media coverage focused on solving the problem. The most sensible answer I saw, that was quoted in the BBC, comes from one Weiho commenter who writes: ”The total weight of 26 sheep and 10 goat is 7,700 kilograms, based on the average weight of each animal.” Now I did a little bit of fact-checking; you would actually get 7,700 POUNDS, if you did this search in Wolfram Alpha, but, let’s just forget this little nitpick and go with 7,700 kilograms, so continuing that response: ”In China, if you’re driving a ship that has more than 5,000 kilograms of cargo, you need to have possessed a boat license for at least five years. The minimum age for getting a boat’s license is 23, so [the captain is] at least 28.” That’s a remarkable leap in logic. But if it sounds too crazy for you, keep in mind that these kinds of deductions are very common in Sherlock Holmes stories. Take an example from ”The Hound of the Baskervilles”. From examining a walking stick of a man he has NEVER met, Sherlock Holmes deduces the man is under 30 years old, is a family doctor and that he owns a dog. So, the official response in China, is that the question was not a mistake. It was actually meant to be open ended and encourage critical thinking, which is usually not present in Math class. That would be the end of the story, except this problem did NOT have its source in China. The real story is the problem was originally asked by French researchers in 1979. This problem is nearly 40 years old! I learned about the problem’s origin from Benjamin Dickman, who has a PhD in Mathematics Education from Columbia University. Benjamin heard about the problem, because he believes that many people in math education have heard about this problem in similar problems, and he tweeted about it. You could check out his Twitter profile twitter.com/benjamindickman So from the sources that he tweeted and sent, we can actually find, in 1979, French researchers asked first and second graders the following problem: “On the boat, there are 26 sheep and 10 goats. What is the age of the captain?” I couldn’t believe it when I was seeing this! This problem has been asked nearly 40 YEARS AGO in ALMOST EXACTLY the same wording! So what was the point of this exercise? Well, from reading some of these sources, the researchers had expected that most students would think the question is absurd. The correct answer would have to be “there is not enough information”, But what they found was shocking. More than 3/4 of students actually tried to solve the problem by manipulating the numbers. They said something like ”Okay, the age must be 26 plus 10, which equals 36.” Very few students questioned if the problem was even solvable. In fact, this was not just a fluke result. The study was replicated on a larger scale in countries including France, Germany and Switzerland, even by researchers, who thought this was not even possible. They were antagonistic to this hypothesis that students would just manipulate numbers, and they found the same thing. Gene Wirchenko emailed me about this related problem. His blog has math and logic problems, usually simpler than mine, and it has other posts. You can visit his blog at genew.ca So, the related question is the following: “There are 125 sheep and five dogs in a flock. How old is the shepherd?” Well once again, you would expect the ”correct” answer, that “there is not enough information” to solve the problem. But, researchers found shocking results again! Many students produced answers by manipulating the numbers in the question. One student reasoned along the following lines: “Well, 125 plus 5 equals 130. That’s too old of an age and 125 minus 5 equals 120, that’s also too old of an age. But 125 divided by 5 equals 25 sounds about right.” So, the student concluded the shepherd is 25 years old. So, what’s the lesson in all of this? The so-called ”Chinese” test question, that went viral was REALLY a French research question from nearly 40 years ago. For such an absurd question, the correct answer is that ”there is not enough information” I give credit to the school in China for asking this question. We still need to improve the critical thinking skills of students in math class. We still keep thinking that every problem we get is solvable, and it should be solvable just by manipulating the numbers we get We should always think ”Does the question actually make sense?” and ” Is there enough information to solve it?” So that’s the real story to this viral math question from China. Thanks for watching this video. Please subscribe to my channel, I make videos on math. You can catch me on my blog, mindyourdecisions.com/blog/ If you like this video, you can check out my books which are linked in the video description, and you can support me on Patreon. If you have a suggestion for a puzzle or a math topic, you can email me at presh [at] mindyourdecisions [dot] com And you can also catch me on social media either at MindYourDecisions or @preshtalwalkar.

100 thoughts on “The REAL Answer To The Viral Chinese Math Problem “How Old Is The Captain?””

  1. The entire worldwide media missed the actual history of this problem! Please tweet this at any news organization that posted a story so they can share the real story dating back to French researchers in 1979.

    Update comment from Markus Schütz (also noted in tweet by Benjamin Dickman): "Actually the origin goes back to 1841: https://en.wikipedia.org/wiki/Age_of_the_captain. In french speaking areas "… and what's the captain's age?" is a very popular saying when someone tells you a story with many unrelated details, or poses a problem in a very complicated wording, or gives you an unsolvable problem. And everyone knows that the correct answer is always "42" ;-)"

    Also, some minor clarifications/corrections and one elaboration:

    3:06 – A more accurate description is: Benjamin Dickman, who has a Ph.D. in Mathematics Education from Teachers College, Columbia University, and currently teaches math at The Hewitt School, an all girls day school in New York City. Benjamin believes such problems are well-known to math education researchers, specifically those with interests in sense-making, problem solving, and problem posing.

    5:02 – the blog "has other posts, too"

    Gene Wirchenko suggested elaborating the ending of the video with this point: (http://genew.ca/solving-the-right-problem-right/)

    "Mathematical tools have requirements for their use. For example, if one has two of voltage, current, and resistance for some types of electrical circuits, one can compute the third using the formula E=IR. BUT you must have two of the values. If you only have one of them, you do not have enough information.

    "In a real world problem, you may have to hunt down the missing information. Sometimes, you can compute a missing value from other information given in the problem.

    "For example, in the problem 'Albert has 25 marbles more than Carl does. Beth has 45 marbles. Carl has 15 fewer marbles than Beth. How many marbles does Albert have?', Albert has c + 25 marbles. We do not know the value of c, but we do know that c = b – 15. That still is not enough, but since we know b = 45, we can substitute 45 for b to get c = 45 – 15 = 30 and then for c in a = c + 25 to get a = 30 + 25 = 55. Thus, Albert has 55 marbles."

  2. So I would split the problem identified by the researchers into two semi-separate issues:
    1) assuming that every problem has an answer (and that there is only ONE such answer, and that it a specific, precise answer)
    2) that the answer can always be found from elementary (random) arithmetic operations on whatever numbers are found explicitly written in the problem, without reference to whatever words/other info are provided.

    Which is the more serious issue? I would say the first.
    The second shows an utter lack of mathematical thinking, so you could argue that is worse, and I wouldn't disagree in a way. But that issue is also the less challenging one to correct; it's an issue of teaching "how best to figure out an answer". Still hard (I teach high school math, so I know just HOW hard!). But in a sense it's simply mastering well-defined algorithmic thinking.

    The first issue however is much harder to instill, especially in school children who've been brought up to expect a simple one to one correspondence between every problem and a single solution to it. But the same issue, broadened to not just math but economic or life decisions, explains much of why we make such poor decisions as adults. I think if we exposed school children to more realistic open-ended problems, practicing and discussing them on a regular basis, they would become more thoughtful in not only their math problem-solving (thus making the second issue disappear too), but hopefully those habits would then translate into life decision-making as well.

  3. The captain is 28+40=68 years old now and enjoying his retired life ……the question was asked about 40 years ago lol

  4. TLDR: The question was an open-ended one and part of an experiment to get students to think critically. Some students worked it out based on knowledge of their country's boat licensing laws, while most, surprisingly, simply tried arithmetic with the numbers they were provided and submitted the result.

  5. If a rocket launch at 690 km/hr at the same time another rocket launch at 690.00 km/hr.Calculate the distance between the 1st Rocket and 2 nd by addition

  6. I'm hungry
    And I dont know what I'm gonna eat
    How many tears will drop from my face because I can't decide what I want to eat?😥😥😥😥😥😥😥😥

  7. Well, I assumed that the obviously incorrect question requires some witty answer rather than a formally correct one. E.g., if it were 2 of each, it could be Noah; my version was, 26 and 10 are letters and digits, so the captain is a kid who just learned them – 6 years old.

  8. i have 3 apples…today i eat 1…how many apples do ihave tomorrow?
    the correct answer : 3 cause my friend will give me 1
    at least you could say there is not enough information rather than saying 2!!!

  9. Since Lionel Messi is the only one capable to be the captain, besides the 9 other goats and sheep, the captains age is 32 years old

  10. Myd- u can solve this question by a short trick and in less time
    Also myd took 7min 23 sec to relate answer that it can't be determined 🤣🤣

  11. Good evening sir ,
    I am having one doubt. Kindly solve this
    What is the number 88, if 8.8 is 54?
    Answer is not 540
    It's correct answer is 104 but plz tell how…

  12. Good video and well worth making. I'm not surprised there are many children who just throw the numbers together and offer an answer. From individual tutoring work that I do I know that kids who are struggling tend to just guess what to do. They are totally lost and trying to bluff their way through. I would be in favour of more exercises where a solution cannot be found because in practical use of mathematics that is often the case. We get little practice at identifying problems that cannot be solved or the more subtle case of problems based on situations that are logically impossible.

  13. I had 2 boil egg in dinner.. after that I took 2 Kms walk… it's 2 am and I am watching this video.. calculate my age.

  14. My conclusion was simple. I have wasted 7 minutes on a puzzle I knew to have no solution and would never even think about sharing.

  15. Captain is flying,so he is a freely falling body so he has no weight and by the law of thugonomics he was never born🤣🤣,so his age is same as that of his grandfather i.e. 3 days

  16. It's a wrong answer how could be the total weight is 7700kg
    If you take avg weight of each sheep and goat will be 213.8kg so it's not possible that sheep's are much not weight 😄😄😄😄

  17. Ambiguous questions are annoying in Maths exams. I remember about 30 years ago in high school I had a couple of them and pointed this out to the teachers at the time. They agreed.
    Children learn in maths that their are answers to questions. In when I was about 15 or 16 we had one teacher give us an unsolvable question. We weren't told it was unsolvable. She wanted to see how we where going to try and solve it. I think it's rare that children get taught about deconstructing language and actually learning what a sentence is trying to tell you.
    The Asian style of educatoin is usually just being told about the solution or how to think about a problem. I'm talking about Vietnam,China etc. Children don't really learn much to do with how to actually solve a problem that's not in a book or the teacher is telling them. This is just a symptom of that. Learning how to solve a new unknown problem is really important. Especially when young.

  18. It all depends on what age you feel it is appropriate for children to actually learn that sometimes you will be asked to solve a problem for which there truly isn't enough information, but you damn well better come up with something because the person asking definitely isn't going to accept, "Based on what's presented, I can't figure it out for sure." It seems like the ones that tried to come up with an answer have learned to critically think about the situation, and determined that, in their specific case, "I don't know" wasn't an acceptable response.

  19. To have 26 sheep and 10 goats on-board, the ship's captain must be at the right age. Therefore, he's in the LEGAL AGE.

  20. What if we answered this way:

    The age of the captain depend on year he was born. If he was born on 1945, he is now 74 years old. If he was born in 1968, he is now 51.

  21. This video proves my point that a lot of scientists' conclusions are a load of crap. They do the same thing as these students, but on a larger scale…they come to conclusions without all the information required to come to an accurate conclusion… guesses and speculation. Critical thinking my friends! Don't believe everything you're taught in school.

  22. I have a couple of questions.
    1. Why does this video have so many dislikes?
    2. How in the world did this video show up in my recommendations lmaoooo

  23. You are a bus driver. On the first stop 5 people get on the bus. On the second stop 3 people get on and 2 get off. On the third stop 7 people get on and 5 get off.

    Based on Bill Gates's salary, on a scale from 1 to 10, to the nearest ten, what is the diameter of the surface area of the sun in cubic ounces? Remember to express your answer in complex form and consider all the colors of the alphabet.

  24. In china, there's a particular age for a ship's captain to be allowed to carry this number of animals on board.
    So that age limit is the answer.

  25. Did you guys know that this problem is nearly 40 years old? Did I tell you that it was first asked nearly 40 years ago? The problem, the one in the video, is nearly 40 years old. If you wanted to know the age of the problem, it's nearly 40 years. Nearly 40 years ago this problem was first asked. Asked nearly 40 years ago for the first time was this problem.

    Like, dude… C'mon. At least mention once or twice that the problem is nearly 40 years old. People might miss that the problem is nearly 40 years old if you don't mention that it's nearly 40 years old. How else would I know it's nearly 40 years old? It's not like you mention that it's nearly 40 years old 152 times in your video or anything.

  26. Q: If your mother is a hoe & your father is a rake, how many pancakes does it take to cover the doghouse roof ? A: None, because footballs don't have wheels. orff orff

  27. My grand-father told me that joke before 1979 when I was a kid. When I said "I don't know", he replied "Just ask him !". Also, it is common in France when you detail a complex calculation to a friend or colleague to insert for fun (but speaking normally) in your demonstration "..and divided by the age of the captain, this yields…" 😄

  28. Actually, according to Wikipedia, it seems that the first appearance of this problem was in a letter that Gustave Flaubert (French writer) wrote to his sister back in July 1841 : https://gallica.bnf.fr/ark:/12148/bpt6k6533968v/f97.image.r=Flaubert%20correspondance (in French)

  29. 我認為這題其實是在考學生的國文程度
    會把數字加起來當答案的表示他根本看不懂大多數的字吧

  30. after i wasted my 7minutes23seconds in my life, i wasted another 10minutes to scroll through comment for random questions and answers, then i wasted 30seconds to type my comment just to get likes, but i cant get.

  31. As this q is 40 years old and the min age to posses a license in any country must be 20 so he must be of 60 years or older now….but if we see for being a captain staying fit is a must which is the reason 70+ age can be avoided as because till this age most of us reitre…so my ans wud be anywhere between 60 to 70.

  32. So the morale of this video is,…. the Chinese are teaching logic and open critical thinking based on an old European question, while the rest of the free world is baffled by them for asking this math problem?

  33. This is why everything made in China breaks. I get that it's origin is French. This also explains why France loses every war. The invading force may have 37 sheep and 407 goats. How do we mount a proper defense?

  34. Can you say 'This problem is not Chinese, but rather French' maybe like 5 more times, maybe that'll help us get off.

  35. When I was a kid, this question was presented as a riddle with a slight twist. The riddle: "You are the captain of a ship that is transporting 12 goats, 20 sheep and 18 head of cattle. How old is the captain of the ship?". Correct answer: age of the listener. But when you're a second grader, you miss the part about who is captain..

  36. The real answer is, the world has become what it is today because 2nd and third graders were learning 40 years ago that they could manipulate data to solve problems and that way of reasoning is encouraged nowadays

  37. If it was an IQ based subject then they answer is valid, but in a subject of mathematics, ….. Hehe what to say….. people are mad.

  38. The reason why students give a simple answer and do not think critically is fault of educating system
    They are basically not enjoying their time in school and learned to solve tasks by luck or the simplest possible way just to finish off their obligations
    The reason why they give that type of answer is purely psychological, nothing fancy here

  39. the real story dating back to French researchers in 1979 said boat?? a boat has no captain but it does have a skipper. a captain is a high grade licensed mariner who holds ultimate command and responsibility of a merchant vessel.. a boat fits on a ship a ship doesnt fit on a boat.. there are many differences between a ship and a boat….

  40. We kill 500 million murderers/criminals to reduce our population. Determine the dimensions of Hell where they will reside.

  41. But if the question was asked 40 years ago, and at that time the captain was thought of being 36 years old, by now the captain must be 76 years old

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