Find the probability of rolling ten different, standard 6-sided dice simultaneously and obtaining a sum of 30?
How many ways can the average of n dice be a?
The close dialog says there are two off-topic votes, but none of the off-topic reasons have votes next to them I've found strange behavior when closing this  - I definitely see that there are 3 closing votes and 2 of them are at "Off-topic" section:   -but there are no explanations on section itself:   -while, normally, it's expected that it will appear. In custom comments section there are also no closing-votes displayed.   Perhaps it's just my browser (which is FF 26 x64 under Win) - so marking this as a "possible bug". Thank you for your attention. Circle Rolling on Ellipse I've gotten interested in describing a circle rolling on an ellipse; specifically, the curve traced out by a point on the circumference of the circle. I want a symbolic solution to the general case, radius $r$, axes $a$ and $b$. I've written nine polynomial equations in terms of various angles and lengths.  Exactly what "solution" means is subject to debate.  Let $(u,v)$ be the point on the circle. Similar to the cycloid, I would like an equation for $u$ in terms of a "natural" angle in the problem.  Similarly, an equation for $v$.  Perhaps it is necessary to have a differential equation, so maybe $du/dt$, $u$, and $t$, where $t$ is an angle in the problem.  I would have thought this was known, but I can't find it anywhere. How to get selected text from textbox control with javascript Notify-send ignores timeout? Maybe I'm doing something wrong, but shouldn't the commands (run separately) notify-send -t 1 &quot;test&quot; notify-send -t 1000 &quot;test&quot; notify-send -t 10000 &quot;test&quot;  have different timeouts? The first being nearly instantaneous, the second taking 1 sec and the third 10 seconds? In all cases it seems to take about six seconds for me. Is there a way around this behaviour? As the developers label this as a &quot;feature&quot; instead of a bug, I would like some alternatives. If I open files I created in Windows, the lines all end with ^M. How do I delete these characters all at once? Unity: How do I revert Alt-tab behavior to switch between windows on the current workspace? Enabling Bias alt-tab sorting to prefer windows on the current viewport as described  made no difference. How can I get back the exact same behavior as 11.04, so that alt-tab only switches between windows on the current workspace?  Simply disabling the alt-tab and shift-alt-tab keybindings on the unity switcher seems to have helped, but it still switches workspaces on me sometimes.  For example, if I give a terminal window focus then press alt-tab, it switches to another terminal window on any workspace before trying to switch on the same workspace. Also, the Unity switcher still shows up when I alt-tab then hold alt even though I removed its alt-tab keybinding. How is my laptop ram running in dual channel? The diagonalizable matrices are not dense in the square real matrices Programmatically combining images in PHP How to ask a smart question The title of  of  is, "Is it posible [sic]?"  This doesn't provide any information at all. It should be mandatory for everyone asking questions on the Internet to read , which says:     Help your community learn from the question. When you field a good question, ask yourself "How would the relevant documentation or FAQ have to change so that nobody has to answer this again?" Include some chat capabilities in iOS app Currently, the app notifies users when they're mentioned in chat. However, when we tap on the notification, we got redirected out of the app to Safari.   Is there a chance we can get some chat capabilities in the app, so that we don't have to login again in Safari to quickly reply to the messages?    App version: 0.1.19 09/19/2014 General formula for evaluating integrals of the form $\displaystyle\int_0^\infty x^ae^{-bx}dx$ For example i have the domainname buyhouse.com The keywords "buy house new york"  buyhouse.com/new-york/   buyhouse.com/buy-house-new-york/   Whats the best url option for SEO? I am looking for an English translation of Markov's 1958 paper, On insolubility of the homeorphy problem, which I remember coming across on a website for a computational topology course (taught by Afra Zomorodian). How many questions on meta have asked, "Why can't I ask this question when that question is open"? What is Skynet's ultimate goal after defeating the resistance? Is it stated in any expanded universe what Skynet's plans were after wiping out the Human race (assuming that was its plan)?  Maybe space travel to colonise different planets or something else entirely? Question on the correlation between two dependent variables I'm working on this question and it's stumping me.     Let $S_n = X_1 + \ldots + X_n$ (with $n&gt;=1$) be a random walk with $X_1, \ldots, X_n$ be iid RV's.   $$ E(X_k)=\mu,\,{\rm Var}(X_k)=\sigma^2.  $$   Find the covariance of $S_n$ and $S_m$   Can anyone help out? I am trying to use the equation: $${\rm Cov}[S_n, S_m] = E[S_nS_m] - E[S_n]E[S_m]$$  but can't quite figure it out. If a mass moves close to the speed of light, does it turn into a black hole? I have a folder on my desktop which is named ".." (which itself contains subfolders with an empty name). The folder can't be deleted the usual ways, even not when using the CLI. Does anyone know how I can remove this folder on Windows Vista 64-bit?  Renaming does not work, either (obviously).  This is what "dir /x" echoes:  09.10.2009  15:04    &lt;DIR&gt;                       . 09.10.2009  15:04    &lt;DIR&gt;                       .. 08.03.2007  11:18    &lt;DIR&gt;                       cgi-bin                0 Datei(en),              0 Bytes                3 Verzeichnis(se), 45.866.037.248 Bytes frei Please revisit the CAPTCHA & China issue Back in 2012 when China first blocked all Google services, thereby preventing non-VPN users from proving their non-roboticness, someone quickly opened this thread on Meta:    The consensus at the time was "we can't think of a better way of doing things".  Well, 3 years have passed and China is showing no signs of unbanning Google. Meanwhile, CAPTCHA technology has evolved. Can the SE admins please revisit this situation? People in China without a VPN are completely unable to prove they are not bots. I couldn't even search for the phrase "pgp" on Security.SE without hitting the human verification barrier. Blocking questions is one thing, but searches also? I think that's too strict.  (yes, I wrote this with my VPN)