Last active
August 29, 2015 14:19
-
-
Save mattantonelli/4ee3a3ddca0dc1ae2f6f to your computer and use it in GitHub Desktop.
Singapore Math Problem
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Albert knows the month. Bernard knows the day. | |
| May 15 May 16 May 19 | |
| Jun 17 Jun 18 | |
| Jul 14 Jul 16 | |
| Aug 14 Aug 15 Aug 17 | |
| Albert does not know the date because all months have more than one day. Albert knows that Bernard | |
| cannot know the date. Therefore, Albert knows that the month contains no uniquely identifying days. | |
| Unique days: 18, 19 | |
| Jul, Aug | |
| (May 15) (May 16) (May 19) | |
| (Jun 17) (Jun 18) | |
| Jul 14 Jul 16 | |
| Aug 14 Aug 15 Aug 17 | |
| Knowing the month is either Jul or Aug, Bernard now knows the date. Therefore, the day cannot | |
| be shared between Jul and Aug. | |
| (May 15) (May 16) (May 19) | |
| (Jun 17) (Jun 18) | |
| (Jul 14) Jul 16 | |
| (Aug 14) Aug 15 Aug 17 | |
| Albert also knows the date now. In order for Albert to know the date, he must be able to uniquely | |
| identify it by the month. Since only one month remaining has a unique date, the date is: | |
| Jul 16 |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Since you know Albert KNOWS the date, and there is only one unique month, you solved it.