| Title: | Mathematics at DEC |
| Moderator: | RUSURE::EDP |
| Created: | Mon Feb 03 1986 |
| Last Modified: | Fri Jun 06 1997 |
| Last Successful Update: | Fri Jun 06 1997 |
| Number of topics: | 2083 |
| Total number of notes: | 14613 |
Proposed by Stanley Rabinowitz, Westford, Massachusetts.
The number 3774 is divisible by 37, 34, and 74 but not by 77. Find
another 4-digit integer abcd that is divisible by the 2-digit numbers
ab, ac, ad, bd and cd but is not divisible by bc.
[No computers. That would be too easy. -- edp]
| T.R | Title | User | Personal Name | Date | Lines |
|---|---|---|---|---|---|
| 2010.1 | Two solutions | FLOYD::YODER | MFY | Tue Oct 31 1995 17:04 | 5 |
The given solution sticks together 37 and 2*37, and it seems plausible that you might want to try xy and 5(xy)--the fact that 2|10 seems to help. For this to work the first digit x must be 1, and if the second digit y is odd the result will be divisible by 15. Trying 1155, 1365, 1575, 1785, and 1995 reveals that 1155 and 1995 work. | |||||
| 2010.2 | Correction! | DECADA::YODER | MFY | Wed Nov 01 1995 09:49 | 5 |
I should be made to write "I will not respond when I'm eager to get home" 100 times on the blackboard. Of course 1155 isn't a solution because the number formed from the center pair of digits is suppposed to NOT divide 1155. However, 1995 is a genuine solution. | |||||
| 2010.3 | RUSURE::EDP | Always mount a scratch monkey. | Mon Oct 14 1996 11:35 | 17 | |