I am helping to correct some errors in a game manual not originally written in english. I've come across a bit that I'm not sure what to do with.  The game consists of several 90-minute matches.  My question is whether this is correct or if the line should read:  The game consists of several 90-minutes matches.  I feel like the original version is correct, though I only base this off of the fact that is "sounds" right to me. I've done a bit of searching and found a blog post about something similar . It doesn't provide a definitive answer though.
Why are year, pound and mile in the singular form in the phrases below?   five-year-old children  20 pound note 10 mile run   Is that because they're acting as adjectives, which are always invariable in English?  Is it incorrect to say...   five-years-old children? 20 pounds note? 10 miles run?
What is the best way to identify outliers in multivariate data? Suppose I have a large set of multivariate data with at least three variables. How can I find the outliers? Pairwise scatterplots won't work as it is possible for an outlier to exist in 3 dimensions that is not an outlier in any of the 2 dimensional subspaces.  I am not thinking of a regression problem, but of true multivariate data. So answers involving robust regression or computing leverage are not helpful.  One possibility would be to compute the principal component scores and look for an outlier in the bivariate scatterplot of the first two scores. Would that be guaranteed to work? Are there better approaches? How can I make a deepcopy of a function in Python? I have been taught to use the if I had form in conditional clauses referring to the past:     If the president had asked me, I would have told him the same thing.   As far as I can tell though, the would have construct is sometimes used in conditional clauses as well, so it wouldn't be incorrect to say:     If the president would have asked me, I would have told him the same thing.   What is the difference between the two and the proper use of the latter? How can I hide my code in visualforce page? I developed my app,   The controller is complete, and also the visualforce, but I need to hide my code at installing the app in another salesforce account.  How can I make this possible?  Is there any way to hide both codes? The apex and the code behind?   Thanks in advance. 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? How to deal with SQL column names that look like SQL keywords? One of my columns is called from. I can't change the name because I didn't make it. Am I allowed to do something like SELECT from FROM TableName or is there a special syntax to avoid the SQL Server being confused? From 2012 onward the SQL Server docs show they support  which I'm trying to use instead of a LIMIT.  The following works fine in PostgreSQL to sample a result set,  SELECT * FROM ( VALUES (1),(2),(3) ) AS t(x) OFFSET 0 ROWS FETCH NEXT 1 ROWS ONLY;   However, with SQL Server, I get  Msg 153, Level 15, State 2, Line 4 Invalid usage of the option FIRST in the FETCH statement.   What's going on here? Does SQL Server support the standardized OFFSET .. FETCH? Gravatar links on "Filtered Questions" page are not HTTPS I have lecture notes with the claim $(C_b(X), \|\cdot\|_\infty)$, the space of bounded continuous functions with the sup norm is complete.  The lecturer then proved two things, (i) that $f(x) = \lim f_n (x)$ is bounded and (ii) that $\lim f_n \in \mathbb{R}$.  I don't understand why it's not enough that $f$ is bounded. I think the limit of a sequence of continuous functions is continuous and then if $f$ is bounded, it's in $C_b(X)$. So what is this $\lim f_n \in \mathbb{R}$ about? Many thanks for your help. Linux GUI development I have a large GUI project that I'd like to port to Linux. What is the most recommended framework to utilize for GUI programming in Linux? Are Frameworks such as KDE / Gnome usable for this objective  Or is better to use something more generic other than X?  I feel like if I chose one of Gnome or KDE, I'm closing the market out for a chunk of the Linux market who have chosen one over the other.  (Yes I know there is overlap)    Is there a better way? Or would I have to create 2 complete GUI apps to have near 100% coverage?  It's not necessary to have a cross-platform solution that will also work on Win32. $\operatorname{Aut}(\mathbb Z_n)$ is isomorphic to $U_n$. If I read the sentence     Find ten apples and oranges.   Do I need to find ten or twenty pieces of fruit? Why should I declare a virtual destructor for an abstract class in C++? I know it is a good practice to declare virtual destructors for base classes in C++, but is it always important to declare virtual destructors even for abstract classes that function as interfaces? Please provide some reasons and examples why. Is there a way to see that $ \nabla_\mu g_{\nu \rho} = 0 $ without explicit computation, where $\nabla_\mu$ refers to the covariant derivative? In books, it is usually said that this is a consequence of the fact that parallel transport preserves dot product. How ? Word for a person who knows two or three languages A polyglot is a person who is fluent in many languages, but what do we call a person who is fluent in only two or three languages?  Is bi-glot a proper term for this?  I don't think the words bilingual / trilingual fit the bill, because I am looking for a -glot word. Case insensitive searching in Oracle Why does a cork float to the side of a glass? Why does a cork ball float to the side of a glass as illustrated in the following GIF? What is the physical phenomenon behind this observation and why does it happen? What part of speech are non-human "interjections" like "oink" and "bang"? As a spin-off from :  If a human exclaims something like "ouch!", I believe it's considered an interjection.  But if a pig exclaims "oink!", what is the part of speech?  And if a bell goes "bong!", what is the part of speech?  You could speak of "an oink" and "a bong" as nouns, but I mean in a context like      The man went "ouch!", the pig went "oink!" and the bell went "bong!"   Are interjections only for humans? rm: cannot remove directory/: Permission denied I made a directory called "shadi" and set this permission for it  sinoosh@ubuntu:/home$ ls -ld shadi drwxr-xrwx 2 root root 4096 Jul  1 01:58 shadi   In this situation I have "others" permissions, but why can I not delete it?  sinoosh@ubuntu:/home$ rm -r shadi/ rm: cannot remove ‘shadi/’: Permission denied How can I launch a GameObject at a target if I am given everything except for its launch angle? I am trying to launch an object at a target, given its position, its target position, the launch speed, and the gravity.  I am following this formula from :  $$ \theta = arctan \bigg( \frac{v^2 \pm \sqrt{v^4-g(gx^2 + 2yv^2)}}{gx} \bigg) $$  I have simplified the code to the best of my ability, but I still cannot consistently hit the target.  I am only considering the taller trajectory, of the two available from the +- choice in the formula.  Does anyone know what I am doing wrong?  using UnityEngine;  public class Launcher : MonoBehaviour {     public float speed = 10.0f;      void Start()     {         Launch(GameObject.Find("Target").transform);     }      public void Launch(Transform target)     {         float angle = GetAngle(transform.position, target.position, speed, -Physics2D.gravity.y);         var forceToAdd = new Vector2(Mathf.Cos(angle), Mathf.Sin(angle)) * speed;         GetComponent&lt;Rigidbody2D&gt;().AddForce(forceToAdd, ForceMode2D.Impulse);     }      private float GetAngle(Vector2 origin, Vector2 destination, float speed, float gravity)     {         float angle = 0.0f;          //Labeling variables to match formula         float x = Mathf.Abs(destination.x - origin.x);         float y = Mathf.Abs(destination.y - origin.y);         float v = speed;         float g = gravity;          //Formula seen above         float valueToBeSquareRooted = Mathf.Pow(v, 4) - g * (g * Mathf.Pow(x, 2) + 2 * y * Mathf.Pow(v, 2));         if (valueToBeSquareRooted &gt;= 0)         {             angle = Mathf.Atan((Mathf.Pow(v, 2) + Mathf.Sqrt(valueToBeSquareRooted)) / g * x);         }         else         {             //Destination is out of range         }          return angle;     } }