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. It's 50 km from town A to town B, & 68 km from town B to town C. How long will it take for a person in town A to smell a fart produced by a person in town C?

  3. In the second example, don't understand how dividing the number of sheep by the number of sheepdogs would give the age of the shepherd.

  4. My daughter is in second grade and I train with her math every day. Tasks with the question if they are solvable or not based on the information given are routine to her. But getting partial results on partial information is still above her expertise and understanding.

  5. This the kind of questions they test you about after just learning how to count. Lmao if Jill can run 5 miles in 1 hour how many watermelons does Jack have.

  6. This reminds me of our electronics professor.

    Cannot be solved

  7. The ship ( had ) but not now…so maybe the ship sank and the captain (human/nonhuman) died and is no more old…

  8. Crap, the age of the captain is dependant on the HORSE power of the boat's engine, not sheep nor goats 🙂

  9. If Emma has 5 apples and in the forest are 700 trees, how old is the capitan

    Answer: ALIENS DON'T WEAR HATS

  10. I have heard such type of ques. but in those, the problem is asked verbally and is started as : " You are driving a bus and it has 20 ladies and 15 gents. Then tell the age of bus driver. "
    This problem in my opinion is absurd.
    The captain might not have a license or may be involved in illegal acts etc.
    Also in the problem of such type we are asked if we can draw some conclusion about the age.

  11. You can only determine how long the captain has been on the ship, not how old he is. (and that part is easy: assuming he has sex with 1 sheep per day and eats one goat per week, he has been on the ship for 26 – 10 weeks because there were originally as many goats as sheep and no sheep or goats have died in the interim. He also only has 5 years left to live because of contracting syphillus from the sheep. This is one of those imagination questions where you have to supply the missing data).

  12. The question itself is already categorically wrong!!!! They shld hv asked for the estimated age and why, cos there isnt a answer to the question only probable one! Thats a foolish way to make judgement on the student for a lousy question!! Fire the examiner!

  13. China is a country without law. The authorities control every single answer of all aspects.

  14. Right so my dog is African, I like scrambled eggs. What is my 3rd favorite reptile

  15. What a silly, nonsense ques… Chinese have doggy brain because they eat dogs…
    In a house there are 5 dogs & 6 bitches. What is the number of bricks used in 3-storey house???

    {Hint: 40 years}
    Ans: 40 years ago.

  16. If my brother is a boy and he has 3 dogs, then find out my brother's name…..

  17. If a ship has 20 N with a direction of 30 ° E of N going to Port, who is the father of those 8 children?

  18. All student know that no enough information givin in the problem but they lack self confidence to say that.

  19. 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.

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

  21. 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.

  22. Okay We got it, its nearly 40 years old no need to remind us of it every 10 seconds

  23. Only backbenchers can answer this question whether it may correct or not

  24. I have a better question. If I have $2.35 in my pocket, what is the colour of my pants. Beat that.

  25. I said "irrelevant" but I thought the x>28 was a good answer 😀

  26. 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

  27. 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?😥😥😥😥😥😥😥😥

  28. 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.

  29. 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!!!

  30. 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

  31. I play 25 hours a day and drink water every 9 hours, how long is Ricardo Milos?

  32. Oh, but you forgot to tell that this was actually a French research question from "NEARLY 40 YEARS AGO!"

  33. If I have 3 friends and have 9 subjects in school, How long was i depressed all this time?

  34. If the speed of a train is 120 km/h,and the wind come from north,What the speed of Wi-Fi in Mars?

  35. 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 🤣🤣

  36. 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…

  37. Teacher, I was late for school because my mama tied my shoelaces too tight and I couldn't breathe.

  38. 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.

  39. 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.

  40. I am wondering the teacher who awarded scores to the students should be interviewed !

  41. The answer is:

    If I slap you with a right hand into right ear – which shoe will untie.

  42. 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.

  43. 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

  44. 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 😄😄😄😄

  45. 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.

  46. 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.

  47. 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.

  48. As seen in the memes, that's how many people think of the excercises in physics books.

  49. 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.

  50. Can not be determined by the question asked. Ask the captain himself how old he is.

  51. This problem was asked by 5th grade and. 5th grade students are nearly 10 years old…..

  52. 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.

  53. 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

  54. What if the sheep and goats are being smuggled? Then the captain might be unlicensed and younger!

  55. 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.

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