MindYourDecisions now has over 1,000 free articles with no ads thanks to community support! It costs thousands of dollars to run the blog and your support matters. Here is a problem from their entrance exam. By way of history, I started the Mind Your Decisions blog back in 2007 to share a bit of math, personal finance, personal thoughts, and game theory. Please check your local Amazon website for availability and program terms. You can sign up for the newsletter here: Sharing Salary Information Secretly (Ft. Feel free to send me an email [email protected]. D E C I S I O N S . Math Puzzles Volume 2 is a sequel book with more great problems. Notice the triangle ADC has two legs 9 and 12, which are triple the legs of 3 and 4 in a 3-4-5 right triangle. Or keep reading for a solution. I studied Economics and Mathematics at Stanford University. Sources Question at MIT archives https://libraries.mit.edu/archives/exhibits/exam/algebra.html, Answer at MIT archives https://libraries.mit.edu/archives/exhibits/exam/algebra-answers.html. The Joy of Game Theory: An Introduction to Strategic Thinking, https://mindyourdecisions.com/blog/my-books, 40 Paradoxes in Logic, Probability, and Game Theory, The Irrationality Illusion: How To Make Smart Decisions And Overcome Bias, https://libraries.mit.edu/archives/exhibits/exam/algebra.html, https://libraries.mit.edu/archives/exhibits/exam/algebra-answers.html. If e = 8, find the numerical value of the following expression: If this question seems easy to you, keep in mind this was part of an entrance exam in 1869, so it must have been difficult enough that some people missed it. Be prepared–animation is time consuming and software can be expensive! MindYourDecisions now has over 1,000 free articles with no ads thanks to community support! This does not affect the price you pay.). The Massachusetts Institute of Technology (MIT) is one of the top ranked universities in the world. Volume 1 is rated 4.6/5 stars on 39 reviews. This has only been possible thanks to tremendous support from everyone that watches and shares my videos and blog posts. Grab a mug, tshirt, and more at the official site for merchandise: Mind Your Decisions at Teespring. Included in the subscription you will get access to millions of ebooks. Find the lengths of the perpendicular, and the two legs of the triangle.”. You don’t need a Kindle device: you can install the Kindle app on any smartphone/tablet/computer/etc. US, list of my books (US) UK, list of my books (UK) Canada, book results (CA) Germany, list of my books (DE) France, list of my books (FR) India, list of my books (IN) Australia, book results (AU) Italy, list of my books (IT) Spain, list of my books (ES) Japan, list of my books (JP) Brazil, book results (BR) Mexico, book results (MX). We could use the Pythagorean Theorem to solve for the remaining lengths, which are the hypotenuses of the smaller triangles. We now need to figure out the legs AC and AB. Find the lengths of the perpendicular, and the two legs of the triangle." I have compiled links to programs in some countries below. Help out and get early access to posts with a pledge on Patreon. (rated 4.2/5 stars on 141 reviews). By Presh Talwalkar. Feel free to send me an email [email protected]. I have compiled links to programs in some countries below. MindYourDecisions now has over 1,000 free articles with no ads thanks to community support! Included in the subscription you will get access to millions of ebooks. (4.2/5 stars on 141 reviews), 40 Paradoxes in Logic, Probability, and Game Theory contains thought-provoking and counter-intuitive results. The Joy of Game Theory shows how you can use math to out-think your competition. (I send it 1 or 2 times a year, and I only collect your email to send this news). Math Videos, Math Puzzles, Game Theory. If you buy from a link in this post, I may earn a commission. Math Puzzles Volume 1 features classic brain teasers and riddles with complete solutions for problems in counting, geometry, probability, and game theory. Like many YouTubers I use popular software to prepare my videos. . . Next we simplify the parenthetical expression. Can you solve it? . I have compiled links to programs in some countries below. The triangle CDA is similar to ADB. “The perpendicular dropped from the vertex of the right angle upon the hypotenuse divides it into two segments of 9 and 16 feet respectively. Teachers and students around the world often email me about the books. Mind Your Decisions is a compilation of 5 books: (1) The Joy of Game Theory: An Introduction to Strategic Thinking (2) 40 Paradoxes in Logic, Probability, and Game Theory (3) The Irrationality Illusion: How To Make Smart Decisions And Overcome Bias (4) The Best Mental Math Tricks (5) Multiply Numbers By Drawing Lines, The Joy of Game Theory shows how you can use math to out-think your competition. Math Puzzles Volume 2 is a sequel book with more great problems. As an Amazon Associate I earn from qualifying purchases. As an Amazon Associate I earn from qualifying purchases. My Books (US and worldwide links) https://mindyourdecisions.com/blog/my-books. As an Amazon Associate I earn from qualifying purchases. Please check your local Amazon website for availability and program terms. This question appeared on its admissions exam nearly 150 years ago. I send the newsletter to for book releases and other big news. This does not affect the price you pay. Included in the subscription you will get access to millions of ebooks. Help out and get early access to posts with a pledge on Patreon. 1869 MIT Admissions Test Problem. I get so many emails that I may not reply, but I save all suggestions for puzzles/video topics. In fact, this skill was tested on an M.I.T. (rated 3.7/5 stars on 11 reviews), The Best Mental Math Tricks teaches how you can look like a math genius by solving problems in your head (rated 4.4/5 stars on 38 reviews), Multiply Numbers By Drawing Lines This book is a reference guide for my video that has over 1 million views on a geometric method to multiply numbers. (4.2/5 stars on 141 reviews), 40 Paradoxes in Logic, Probability, and Game Theory contains thought-provoking and counter-intuitive results. And My Reaction to Power-Up, A New Book. The hypotenuse must also be four times the length, so it is 20. Like many YouTubers I use popular software to prepare my videos. Since 2007, I have devoted my life to sharing the joy of game theory and mathematics. As an Amazon Associate I earn from qualifying purchases. If you buy from a link in this post, I may earn a commission. (which was viral in Japan), 6 ÷ 2(1+2) = ? . Currently you can read most of my ebooks through Amazon's "Kindle Unlimited" program. Can You Solve This 1869 MIT Admissions Geometry Question? Here is a diagram that illustrates the given information. I am also the author of The Joy of Game Theory: An Introduction to Strategic Thinking, and several other books which are available on Amazon. Since education can have such a huge impact, I try to make the ebooks available as widely as possible at as low a price as possible. Currently you can read most of my ebooks through Amazon’s “Kindle Unlimited” program. First let’s label a few things, lengths of three segments with question marks above, three angles in the big triangle, and the point along the hypotenuse of the big triangle where the interior line meets it at a right angle: We have three right triangles, one big one, XYZ, and two small ones, XWZ and XYW. YouTube Video – How To Calculate Cube Roots In Your Head, YouTube Video – Multiply Numbers By Drawing Lines, Blog Post – The Best Game Theory Books I’ve Read, Blog Post – Game Theory In The Dark Knight, Blog Post – How Game Theory Solved A Religious Mystery, Blog Post (survey required) – How To Get Straight A’s In College. The triangle CDA is similar to ADB. Please check your local Amazon website for availability and program terms. Learn more. The Massachusetts Institute of Technology (MIT) is one of the top ranked universities in the world. My Books (US and worldwide links) https://mindyourdecisions.com/blog/my-books. M I N D . In the past I have made videos about the order of operations, including the expressions: 9 – 3 ÷ (1/3) + 1 = ? . I thank everyone that has shared my work, and I am very grateful for coverage in the press, including the Shorty Awards, The Telegraph, Freakonomics, and many other popular outlets. (rated 4/5 stars on 23 reviews), The Irrationality Illusion: How To Make Smart Decisions And Overcome Bias is a handbook that explains the many ways we are biased about decision-making and offers techniques to make smart decisions. This has only been possible thanks to tremendous support from everyone that watches and shares my videos and blog posts. It's been quite a journey! Source Questions (see problem 6) https://libraries.mit.edu/archives/exhibits/exam/geometry.html Answers (see problem 6) https://libraries.mit.edu/archives/exhibits/exam/geometry-answers.html. Mind Your Puzzles is a collection of the three "Math Puzzles" books, volumes 1, 2, and 3. I run the MindYourDecisions channel on YouTube, which has over 1 million subscribers and 200 million views. You'll get exclusive content like a free chapter of a book. Learn more. But we can solve for it even faster by noticing each triangle is similar to the 3-4-5 right triangle.