Search Results
| Search type | Search syntax |
|---|---|
| Tags | [tag] |
| Exact | "words here" |
| Author |
user:1234 user:me (yours) |
| Score |
score:3 (3+) score:0 (none) |
| Answers |
answers:3 (3+) answers:0 (none) isaccepted:yes hasaccepted:no inquestion:1234 |
| Views | views:250 |
| Code | code:"if (foo != bar)" |
| Sections |
title:apples body:"apples oranges" |
| URL | url:"*.example.com" |
| Saves | in:saves |
| Status |
closed:yes duplicate:no migrated:no wiki:no |
| Types |
is:question is:answer |
| Exclude |
-[tag] -apples |
| For more details on advanced search visit our help page | |
Results tagged with puzzle
Search options answers only
not deleted
user 1061
Recreational mathematics or puzzles with serious mathematical content. Note that math contest problems are generally considered off-topic.
6
votes
Another colored balls puzzle (part II)
As Douglas Zare points out in a comment to Vincent Beffara's answer, in case 1 the expected time to completion of the process, starting from $(1,n-1)$ is $2^n-1$. To see this, consider a simple random …
- 6,711
18
votes
Accepted
How to get rich in a Hilberts Hotel?
No, you cannot get rich with identical copies on the unlabeled tree. This is a special case of the Mass Transport Principle - take a look at the book of Lyons and Peres, chapter 8.
- 6,711
17
votes
Identifying poisoned wines
You yourself give the solution in the link: the probabilistic method. Without trying to optimize, take $r$ rats and for each one choose the subset of wines randomly, each wine with probability $1/2$ ( …
- 6,711
30
votes
Accepted
A balls-and-colours problem
It can probably be done by looking at the sum of squares of sizes of color clusters and then constructing an appropriate martingale. But here's a somewhat elegant solution: reverse the time!
Let's fo …
- 30.1k