what are the odds from 5 persons, to at least 2 be born at the same day in the week?
What is the chance that at least two people were born on the same day   of the week if there are 3 people in the room?   I'm wondering if my solution is accurate, as my answer was different than the solution I found:  Probability that there are at least 2 people in the room born on the same day = 1 - (No one was born on the same day) - (Exactly one person was born on the same day)  There are (3 choose 2) different pairs of couples. Each couple has the same birthday as another couple with the chances of 1/7 and different with chances 6/7. Thus:  $$1 – (6/7)^3 – 3(1/7)(6/7)^2 = 0.0553$$  Thanks for any help!
Is there any tool available for extracting the X, Y and Z coordinates from a .las file and exporting them to a .csv or similar file? Duplicate explanation should encourage improvement of original The new closed-as-duplicate banner says:     This question has been asked before and already has an answer. If those answers do not fully address your question, please .   I think it should instead say     This question has been asked before and already has an answer. If answers there do not fully address your question, please  or  to the pre-existing one.   &mdash; to discourage re-re-asking the same question. (I also changed "those answers", which has no plural , to "answers there", which doesn't need one.)    As of September 19, 2013, the original text quoted above has returned here. Maximum table size for a MySQL database What is the maximum size for a MySQL table? Is it 2 million at 50GB? 5 million at 80GB?  At the higher end of the size scale, do I need to think about compressing the data? Or perhaps splitting the table if it grew too big? Can every even integer be expressed as the difference of two primes? How best to determine if an argument is not sent to the JavaScript function I have now seen 2 methods for determining if an argument has been passed to a JavaScript function. I'm wondering if one method is better than the other or if one is just bad to use?   function Test(argument1, argument2) {       if (Test.arguments.length == 1) argument2 = 'blah';        alert(argument2);  }   Test('test');   Or   function Test(argument1, argument2) {       argument2 = argument2 || 'blah';        alert(argument2);  }   Test('test');   As far as I can tell, they both result in the same thing, but I've only used the first one before in production.  Another Option as mentioned by :  function Test(argument1, argument2) {     if(argument2 === null) {         argument2 = 'blah';     }      alert(argument2); }   As per Juan's comment, it would be better to change Tom's suggestion to:  function Test(argument1, argument2) {     if(argument2 === undefined) {         argument2 = 'blah';     }      alert(argument2); } If $x\sqrt{1+y}+y\sqrt{1+x}=0$ find $y'$ Find $\frac{dy}{dx}$ if $x\sqrt{1+y}+y\sqrt{1+x}=0$ for $-1\leq x\leq 1$   My Attempt $$ x\sqrt{1+y}=-y\sqrt{1+x}\implies x^2(1+y)=y^2(1+x)\implies x^2+x^2y=y^2+xy^2\\ 2x+2xy+x^2\frac{dy}{dx}=2y\frac{dy}{dx}+y^2+2xy\frac{dy}{dx}\\ \frac{dy}{dx}\Big[ x^2-2y-2xy \Big]=y^2-2x-2xy\\ \frac{dy}{dx}=\frac{y^2-2x-2xy}{x^2-2y-2xy} $$ How do I proceed further and find the derivative ? OpenCV argc and argv confusion Will having multiple domains improve my seo? Lets say I have a domain already, for example www.automobile4u.com (not mine), with a website fully running and all.  The title of my "Website" says:    &lt;title&gt;Used cars - buy and sell your used cars here&lt;/title&gt;   Also, lets say I have fully SEO the website so when people searching for the term buy used cars, I end up on the second or first page.  Now, I want to end up higher, so I go to the google adwords page where you can check how many searches are made on specific terms.  Lets say the term "used cars" has 20 million searches each month.  Here comes the question, could I just go and buy that domain with the search terms adress, in this case www.usedcars.com and make a redirect to my original page, and this way when people search for "used cars", my newly bought domain name comes up redirecting people to my original website (www.automobile4u.com)?  The reason I believe this benefits me is because it seems search engines first of all check website adresses matching the search, so the query "used cars" would automatically bring www.usedcars.com to the first result right?  What are the downsides for this?  I already know about google spiders not liking redirects, but there are many methods of redirecting...  Is this a good idea generally? Do class spells take up spell slots? So I'm fairly new and ended up being the Cleric in my also fairly new group. I haven't played a caster before and the book says that at level 1 I have Bless and Cure Wounds. Do I need to assign these to a spell slot or do I have them inherently (not to be confused with a cantrip; I know I'd have to use a slot to cast them)? How to make the taskbar blink my application like Messenger does when a new message arrive? Two submit buttons in one form I have two submit buttons in a form. How do I determine which one was hit serverside? In Bash, suppose I visit a directory, and then another directory. I would like to copy a file from the first directory to the second directory, but without specifying the long pathnames of them. Is it possible?   My temporary solution is to use /tmp as a temporary place to store a copy of the file. cp myfile /tmp when I am in the first directory, and then cp /tmp/myfile . when I am in the second directory. But I may check if the file will overwrite anything in /tmp.  Is there something similar to a clipboard for copying and pasting a file? Separators for author group (IF conditon) I am new to LaTeX, just a beginner, basically a Perl developer.  I have created a LaTeX file  \begin{document}  \cont{\iname{\isurname{Name1}\ifname{K. C. G.}}\iname{\isurname{Name11}\ifname{Y. Q.}}\iname{\isurname{Name111}\ifname{C.-Z.}}\ititles{Some title Text}\ipage{995}}  \end{document}   Now my need is to define LaTeX commands so that the output should appear as below     Name1 K. C. G., Name11 Y. Q. and Name111 C.-Z. Some title Text - 995.   \iname - Person Name will repeat several times \isurname - Surname of a person \ifname - First Name of a person    \iname will repeat any number of times, say 1 to ...  If only one \iname found inside \cont, display should be like the below     Name1 K. C. G. Some title Text - 995.   If only two \iname found inside \cont, display should be like the below     Name1 K. C. G. and Name11 Y. Q. Some title Text - 995.   If more than two \iname found inside \cont, display should be like the below (and should come after last \iname)     Name1 K. C. G., Name11 Y. Q. and Name111 C.-Z. Some title Text - 995.   I can define input for \iname separated by commas, but I don't know how to write a macro to define \iname with different outputs based on the if condition.  I hope to have clearly explained my doubt. Using the mxd.findAndReplaceWorkspacePaths method, if and MXD is updated and the path the the .sde connection file moves again all of the data sources will break again.   Is there a method to permanently update each SDE layer in an MXD Table of Contents to permanently store the SDE Server and Service? Ie. Just replace the SERVER and INSTANCE for each SDE layer in an MXD using python or ArcObjects in Pyhton? What hardware does Ubuntu Touch support? With the announcement of the Ubuntu Phone OS I'd like to know what phone (and tablet) models are supported at this time.  Note from foss &amp; Oli: We are making this the master question for all future "Will this work on &lt;insert random tablet/phone/device here&gt;?!" questions How to search something on across multiple sites with a single Google query? I tried   (search term site:stackoverflow.com) OR (search term site:superuser.com) OR (search term site:stackexchange.com) search term site:stackoverflow.com,superuser.com,stackexchange.com search term site:stackoverflow.com site:superuser.com site:stackexchange.com   None of them works. What is the correct way to search? #!/bin/bash - no such file or directory I've created a bash script but when I try to execute it, I get   #!/bin/bash no such file or directory   I need to run the command: bash script.sh for it to work.  How can I fix this? Assign multiple colors to features within a single vector layer Why was Enterprise on a five-year mission in TOS? There is a small difference between intro texts in TOS:     Space: the final frontier. These are the voyages of the starship Enterprise. Its five-year mission: to explore strange new worlds, to seek out new life and new civilizations, to boldly go where no man has gone before.   and in TNG:     Space: the final frontier. These are the voyages of the starship Enterprise. Its continuing mission: to explore strange new worlds, to seek out new life and new civilizations, to boldly go where no one has gone before.   (emphasis mine)  It's pretty obvious that no man was changed to no one to include women. But, is there any explanation why was five-year changed to continuing? Also, why was it a five-year mission at all?  My only assumptions are:   Gene Roddenberry hoped to get funding to run the show for 5 seasons. Gene Roddenberry just made up a number without any special meaning. Gene Roddenberry was a .   Is there any official explanation, in universe or not? When articles are placed after adjectives? I couldn't afford that big a car. It was so warm a day that I could hardly work.   The sentences stated above have been taken from Practical English Usage by Michael Swan. If I write-   I couldn't afford that big car. It was so warm day that I could hardly work.   These make sense. But placement of article a makes these sentences awkward to me. Please say why and when articles are placed after adjectives. And what are the differences among 1, 2 and 3, 4.