New answers tagged no-computers
3
votes
Save now! All the digits at half the price
A bit messier than I'd like, but here goes.
As other answers have noted, the doubleable PD10 numbers we want are those where
Let's show that every such number can be specified by:
for an overall ...
- 24.5k
2
votes
7
votes
Accepted
Save now! All the digits at half the price
Let's define some terms:
Now we can begin.
Let's break the problem down now.
Now for the final count!
- 6,922
5
votes
Save now! All the digits at half the price
My guess is:
First, observe that the first digit of $x$:
Then, the reasoning goes this way:
I'm not 100% sure of my calculus but this is how I did it:
- 51
8
votes
Important Alien Message
Not an answer.
Alphabetic transcription of alien writing:
QBADFAHGCAEBACDABEA
FIJCHAEGADFAIEAAHA
DGBACAFEILIAGADBAAA
AAAFCEADHAGBNEAIFAB
HDGAIEFAGCHAFADMEF
AHCABIADACHEGADBAO
AHDACFIEAHDBAGEIAH
...
- 1,278
22
votes
Accepted
Find the lower 8-digits number such that
Solution (0 allowed)
Reasoning
Solution (0 disallowed)
Reasoning
- 130k
6
votes
Accepted
Equilibrium of differences
(NB: I've chosen to interpret "the four numbers Alice chooses must be non-repeatable" as "Alice cannot choose the same digit more than once". There are other possible ...
- 71.5k
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