mersenneforum.org  

Go Back   mersenneforum.org > Fun Stuff > Puzzles

Reply
 
Thread Tools
Old 2018-12-31, 19:40   #1
Batalov
 
Batalov's Avatar
 
"Serge"
Mar 2008
Phi(4,2^7658614+1)/2

3×3,061 Posts
Default 2019 number games

https://www.theguardian.com/science/...019-in-numbers

Quote:
Originally Posted by Ed Southall
2019 is the smallest number that can be written in 6 ways as the sum of the squares of 3 primes:
7² + 11² + 43² = 2019
7² + 17² + 41² = 2019
13² + 13² + 41² = 2019
11² + 23² + 37² = 2019
17² + 19² + 37² = 2019
23² + 23² + 31² = 2019
Then, the rather traditional --
Date jam

1. Using only the digits 2, 0, 1 and 9, create expressions that equal all of the numbers from 0 to 12.
The expressions can include any of the arithmetical symbols +, –, x, ÷ and √, and brackets.

I’ll start you off:

0 x (2 + 1 + 9) = 0
2 – 1 + (0 x 9) = 1
Note: you must use each of the digits 2, 0, 1 and 9 once and only once in each expression.
...and read on.

Happy New Year!
Batalov is offline   Reply With Quote
Old 2018-12-31, 20:02   #2
petrw1
1976 Toyota Corona years forever!
 
petrw1's Avatar
 
"Wayne"
Nov 2006
Saskatchewan, Canada

32·7·71 Posts
Default

Quote:
Originally Posted by Batalov View Post
1. Using only the digits 2, 0, 1 and 9, create expressions that equal all of the numbers from 0 to 12.
The expressions can include any of the arithmetical symbols +, –, x, ÷ and √, and brackets.

I’ll start you off:

0 x (2 + 1 + 9) = 0
2 – 1 + (0 x 9) = 1
Note: you must use each of the digits 2, 0, 1 and 9 once and only once in each expression.
...and read on.

Happy New Year!
(9+1)*0+2=2

NEXT...
petrw1 is online now   Reply With Quote
Old 2018-12-31, 20:10   #3
science_man_88
 
science_man_88's Avatar
 
"Forget I exist"
Jul 2009
Dumbassville

26×131 Posts
Default

Quote:
Originally Posted by Batalov View Post
https://www.theguardian.com/science/...019-in-numbers



Then, the rather traditional --
Date jam

1. Using only the digits 2, 0, 1 and 9, create expressions that equal all of the numbers from 0 to 12.
The expressions can include any of the arithmetical symbols +, –, x, ÷ and √, and brackets.

I’ll start you off:

0 x (2 + 1 + 9) = 0
2 – 1 + (0 x 9) = 1
Note: you must use each of the digits 2, 0, 1 and 9 once and only once in each expression.
...and read on.

Happy New Year!
2=2+(0*1*9)
3=2+1+(0*9)
4=(9-1)/2+0
5=(9+1)/2+0
6=9-2-1-0
7=9-2+(1*0)
8=9-1+(2*0)
9=9+(1*2*0)
10=9+1+(2*0)
11=9+2+(1*0)
12=9+2+1+0
16=(9-1)*2+0
17=9*2-1+0
18=9*2+(1*0)
19=9*2+1+0
20=(9+1)*2+0
27=9*(2+1+0)


just a few guesses.
science_man_88 is offline   Reply With Quote
Old 2018-12-31, 20:29   #4
petrw1
1976 Toyota Corona years forever!
 
petrw1's Avatar
 
"Wayne"
Nov 2006
Saskatchewan, Canada

32×7×71 Posts
Default Dates in 2019 that are All Primes

DISCLAIMER: Standard Date format where I work is: YYYYMMDD.

Dates in 2019 that are prime in all regards.
That is, all the following are prime numbers.

YYYYMMDD
YYYY
MM
DD
MMDD

20190523
20190719
20191117

If you include YYYYMM then only the last 2 numbers above qualify.

This is the only date for which ONLY YYYYMMDD is prime: 20191027

I retired (for the first time) on a date like this in 2011 (20110523)
https://www.mersenneforum.org/showthread.php?t=15616
Interestingly May, 23 is also prime in 2019. Must be a sign? Time to retire again?

Last fiddled with by petrw1 on 2018-12-31 at 20:39
petrw1 is online now   Reply With Quote
Reply

Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
January 2019 Xyzzy Puzzles 74 2019-04-09 13:34
2019 Coding Challenge miroslavkures Number Theory Discussion Group 2 2018-12-27 08:59
Chess games science_man_88 Chess 9 2012-01-24 11:32
Looks like we need to have sane games now... moo Lounge 1 2005-09-01 06:08
Pausing for games... Xyzzy Software 2 2003-09-25 04:25

All times are UTC. The time now is 20:05.

Fri Dec 4 20:05:29 UTC 2020 up 1 day, 16:16, 0 users, load averages: 1.90, 1.54, 1.48

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.

This forum has received and complied with 0 (zero) government requests for information.

Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation.
A copy of the license is included in the FAQ.