HARD Google Interview Question - The 25 Horses Puzzle
There are 25 mechanical horses and a single racetrack. Each horse completes the track in a pre-programmed time, and the horses all have different finishing times, unknown to you. You can race 5 horses at a time. After a race is over, you get a printout with the order the horses finished, but not the finishing times of the horses. What is the minimum number of races you need to identify the fastest 3 horses?\r
\r
I was suggested this puzzle via email by Terry Stickels. This is also a popular interview question at tech companies like Google. See a list of all sources in my blog post for this video:\r
\r
\r
If you like my videos, you can support me at Patreon: \r
\r
Connect on social media. I update each site when I have a new video or blog post, so you can follow me on whichever method is most convenient for you.\r
\r
My Blog: \r
Twitter: \r
Facebook: \r
Google+: \r
Pinterest: \r
Tumblr: \r
Instagram: \r
Patreon: \r
\r
Newsletter (sent about 2 times a year): \r
\r
My Books\r
\r
The Joy of Game Theory shows how you can use math to out-think your competition. (rated 3.8/5 stars on 27 reviews) \r
\r
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. (rated 5/5 stars on 2 reviews) \r
\r
Math Puzzles Volume 1 features classic brain teasers and riddles with complete solutions for problems in counting, geometry, probability, and game theory. Volume 1 is rated 4.4/5 stars on 13 reviews. \r
\r
Math Puzzles Volume 2 is a sequel book with more great problems. (rated 5/5 stars on 3 reviews) \r
\r
Math Puzzles Volume 3 is the third in the . (rated 3.8/5 stars on 4 reviews) \r
\r
40 Paradoxes in Logic, Probability, and Game Theory contains thought-provoking and counter-intuitive results. (rated 4.7/5 stars on 12 reviews) \r
\r
The Best Mental Math Tricks teaches how you can look like a math genius by solving problems in your head (rated 4.7/5 stars on 4 reviews) \r
\r
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. (rated 5/5 stars on 3 reviews)
\r
I was suggested this puzzle via email by Terry Stickels. This is also a popular interview question at tech companies like Google. See a list of all sources in my blog post for this video:\r
\r
\r
If you like my videos, you can support me at Patreon: \r
\r
Connect on social media. I update each site when I have a new video or blog post, so you can follow me on whichever method is most convenient for you.\r
\r
My Blog: \r
Twitter: \r
Facebook: \r
Google+: \r
Pinterest: \r
Tumblr: \r
Instagram: \r
Patreon: \r
\r
Newsletter (sent about 2 times a year): \r
\r
My Books\r
\r
The Joy of Game Theory shows how you can use math to out-think your competition. (rated 3.8/5 stars on 27 reviews) \r
\r
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. (rated 5/5 stars on 2 reviews) \r
\r
Math Puzzles Volume 1 features classic brain teasers and riddles with complete solutions for problems in counting, geometry, probability, and game theory. Volume 1 is rated 4.4/5 stars on 13 reviews. \r
\r
Math Puzzles Volume 2 is a sequel book with more great problems. (rated 5/5 stars on 3 reviews) \r
\r
Math Puzzles Volume 3 is the third in the . (rated 3.8/5 stars on 4 reviews) \r
\r
40 Paradoxes in Logic, Probability, and Game Theory contains thought-provoking and counter-intuitive results. (rated 4.7/5 stars on 12 reviews) \r
\r
The Best Mental Math Tricks teaches how you can look like a math genius by solving problems in your head (rated 4.7/5 stars on 4 reviews) \r
\r
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. (rated 5/5 stars on 3 reviews)
Category
📺
TV