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When is Cheryl's Birthday? Answer To Viral Math Puzzle
- Published_at:2015-04-14
- Category:Education
- Channel:MindYourDecisions
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- description: If you like this video, you'll love my book of math puzzles! Rated nearly 5 stars on 9 reviews on Amazon: http://amzn.to/1bhEsnZ Check out my NEW book "The Best Mental Math Tricks" http://amzn.to/18maAdo This problem went viral after it appeared on a Math Olympiad test for talented students in Singapore. It's not a trick question! Here's the problem, which I have very slightly re-worded for clarity. Blog post (detailed text explanation): http://mindyourdecisions.com/blog/2015/04/14/when-is-cheryls-birthday-answer-to-viral-math-puzzle/ Source: https://www.facebook.com/kennethjianwenz/photos/a.173663129479243.1073741827.167504136761809/385751114937109/?type=1&theater Official Solution: http://mothership.sg/2015/04/p5-logic-question-is-actually-a-math-olympiad-question-for-sec-3-and-4-students/ Albert and Bernard have just become friends with Cheryl, and they want to know when her birthday is. Cheryl gives them a list of 10 possible dates. May 15, May 16, May 19 June 17, June 18 July 14, July 16 August 14, August 15, August 17 Cheryl tells Albert the month and Bernard the day. Albert says, "I don't know when Cheryl's birthday is, but I know that Bernard cannot know either." Bernard then says, "At first I didn't know when Cheryl's birthday is, but now I do know." Albert concludes, "Now I know when Cheryl's birthday is." So when is Cheryl's birthday? If you like my videos, you can support me at Patreon: http://www.patreon.com/mindyourdecisions Connect on social media My Blog: http://mindyourdecisions.com/blog/ Twitter: http://twitter.com/preshtalwalkar Books: http://goo.gl/BDlEkB Facebook: https://www.facebook.com/pages/Mind-Your-Decisions/168446714965 Google+: https://plus.google.com/108336608566588374147/posts Pinterest: https://www.pinterest.com/preshtalwalkar/ Tumblr: http://preshtalwalkar.tumblr.com/ Instagram: https://instagram.com/preshtalwalkar/ Patreon: http://www.patreon.com/mindyourdecisions
| ranked in date | views | likes | Comments | ranked in country (#position) |
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| 2015-04-16 | 37,689 | 162 | 126 |
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