Difference between while and whilst What is the difference between 'while' and 'whilst'? When to use them?
How do I choose between "while" and "whilst"? When should whilst be used instead of while?  For example, should I use the first or the second sentence?      They don't do this whilst they do that.   They don't do this while they do that.   Which would be correct?
Flight cancelled but doesn't show up on status I booked a SpiceJet flight from Dubai to Ahmedabad on Dec 16 (SG-16) scheduled to depart at 7:25 PM. At noon I received an SMS from SpiceJet to advise me that my flight has been delayed by 4h 50m. Sure enough, when I checked flight status on SpiceJet's website, that was the case. But on other websites like flightstats.com and dubaiairports.ae, the status was that flight was "delayed by 2h 25m".    At 5 PM, I got an SMS that flight had been cancelled. I double checked on Spicejet's website and that too showed the flight to be cancelled. But both flightstats.com and dubaiairports.ae still showed the flight as delayed by 2h 25m.    I went to the airport and met SpiceJet officials. Sure enough, the flight was cancelled. But somehow, the flight cancellation status never made it to the system. I have a Tripit Pro account, and even that never sent me an alert for that. I contacted the travel agent through which I booked my flight (makemytrip) for a refund, and they said that their system doesn't show that flight was cancelled. Now, even the Spicejet website has removed the cancellation status from that flight.    Apart from the SMS, I now have no proof that my flight was cancelled.    Can someone tell me, how can I proceed with a refund claim? I am just learning ArcGIS 10.2 and it was working well until I tried to use the Export to a Geodatabase (single) option for a dbs table I made. Since then, it seems I now get the same Script Error for import/export functions. However, I just tried to export to Geodatabase (multiple) and error did not pop up. I spoke with tech support and they could not help me so far. I really do not know much about GIS so it is hard for me to fix this problem and cannot proceed with some things. How can I prove these are the adjoint operators? What follows if we fail to reject the null hypothesis? What conclusions can we draw if $p&gt;\alpha$? Does not rejecting the $H_0$ mean anything? rake db:migrate doesn't seem to work in production Merge pdfs sequentially I would like to merge 4 pdfs, pdf1.pdf, pdf2.pdf, pdf3.pdf pdf4.pdf together so that the pdfs are spliced, i.e. the first page will be the first page of pdf1, the second the first of pdf2, the third the first of pdf3, etc.  The pdf files are with plain images, no table of contents.  How would I accomplish this? It would be nice to do it from Terminal as well. How to flag a typo question I came across  today. In reading the answer and the comments it turns out that the issue was just a simple typo that the OP made. So that being the case I decided that this question probably needs to be closed since this will not be helpful to any future vistors. However, in looking at the flag reasons (I don't have the close ability yet), I don't see a flag that would be appropriate.   I know some of these options might still be influx because of the . However, until a different off-topic flag description is created, how should this be flagged? Or should this not be flagged at all and just allowed to live on or wait for a user with close votes to use a custom off-topic close option? Implicit Differentiation Help I have to use implicit differentiation to find $\frac{dy}{dx}$ given:  $$x^2 \cos(y) + \sin(2y) = xy$$  I don't even know where to begin, I missed the class where we went over implicit differentiation, and because of that, I am completely stuck.   Thank you everyone.  Edit: I don't know how to make the equation look all nice and whatnot, so sorry about that Historical flight data outside of the USA? The question  only deals with flights in the US sourced from the  . Is there some similar source for EU, Asia etc? What benefit do plasterboard/drywall screws have? I have some plasterboard screws like this:     However, without a drill I have a job getting them into the wall. Am I safe to use normal screws on hangings that aren't going to be taking a great deal of weight? In this case it is a rack of coat hooks. SaveAsActivity is not allowed with whatId that is not supported as a task whatId Is it possible to wipe an entire iCloud Photo Library? I've been using the beta iCloud Photo Library for a week and a bunch of photos got duplicated and I'd like to wipe all the photos out and start over.  I have backups of all the photos and have turned off iPhoto Cloud Library on all iOS devices. When I log into the web app - it still shows dozens of albums and I can delete all the photos, then go to deleted items and then purge them, but the ghost albums are still there messing things up.  I've turned off the library entirely and you can see there is a 30 day waiting period.     If I click on albums, there are pages of them and no delete button anywhere. If I turn on the library on an iOS device, data starts flooding back as if I wanted to recover the photos.  I don't want to recover anything, I want a clean wipe and clean slate.  Currently, there are 7807 photos in the deleted album and no way to mass delete them. I have 31 albums that show up in iCloud and no way to delete them.  Is there some way to accelerate this or must people wait a month for a corrupt library to eventually be purged to start over?  (I have tickets open with AppleCare after  and it's escalated to engineering, but I was informed that it might be a week or two before it gets seen :-( Perhaps someone has a better idea to clear things out or noticed something I've missed.) Is an apostrophe with a decade (e.g. 1920’s) generally considered “incorrect”? I typically don’t use an apostrophe with plurals in any situation, but I always assumed that the use of an apostrophe in constructions like acronyms:     Forty BA’s were given out to students this year.   or numbers:     Though the greatest period instability occurred during the 1950’s when. . . .   was more or less ok. I would personally use BAs and 1950s here, but I've never thought the apostrophe in this case was necessarily “incorrect”. What say ye? I understand that they force you to implement methods and such but what I cant understand is why you would want to use them. Can anybody give me a good example or explanation on why I would want to implement this. Finding a distribution from the sum of two random variables in a joint trinomial distribution Let X and Y have a trinomial distribution with join probability function:  $ f(x,y) = \frac{n!}{x!y!(n-x-y)!}p^x q^y (1-p-q)^{n-x-y}; x=0,1,...n, y=0,1,...n$  Let $T=X+Y$  I can't seem to figure out where to go exactly. Here's where I am at:  $\sum_{x=0}^{n} \frac{n!}{x!y!(n-x-y)!}p^x q^y (1-p-q)^{n-x-y}\mbox{ substitute in Y=T-X}$ $\sum_{x=0}^{n} \frac{n!}{x!(t-x)!(n-t)!}p^x q^{t-x} (1-p-q)^{n-t}$   I think I could I figure out the algebra.. if I could just see what to do with the summation. I know I have to involve a t somewhere, but I'm not sure. Maybe somebody could just show me how to set up my summation correctly with the substitution? Fighting Spam - What can I do as an: Email Administrator, Domain Owner, or User? Has 'Ubuntu Software' been renamed to 'Snap Store'? I updated Ubuntu last night (sudo apt get update &amp;&amp; sudo apt get upgrade) and to  my surprise this morning I didn't find the 'Ubuntu Software' app and there's a new entry called 'Snap Store' which when opened looks just like the old 'Ubuntu Software' app. So has 'Ubunu Software' been renamed to 'Snap Store'? And if yes, why? How can I tell which cards or sets are currently legal in various formats? I haven't played Magic: the Gathering since the days of Onslaught and Mirrodin, and I would like to try to catch back up. Since all my cards are quite dated now, I may be more interested in formats other than the most up-to-date one.  Rather than ask what is currently legal in various formats (since that is likely too localized), I would rather pose the question of how can I tell which sets/cards are legal in each format. How to both display a command line's output on console and save the output into a text file? How can I run sudo apt-get install by BOTH seeing the process of installation (long in my case) and saving its output into a text file ? Maximum number of files being uploaded by input type file