So far I've broken it off to:-  $M=1$  $I=2$  $S=4$  $A=2$  $U=1$  $G=1$  However, I don't really know what to do next. An answer (with steps please) would be greatly appreciated. This seems to be a really important question :)
How many different/unique $4$-letter arrangements are there of the letters in the word Mississauga?  I'm thinking we need permutations? I already tried finding each letter and still don't get it... any help?   So far I've broken it off to:-  $M=1$  $I=2$  $S=4$  $A=2$  $U=1$  $G=1$  However, I don't really know what to do next.
Explicitly accept change for PPA 'Label' When I run apt-get update on my ubuntu 17.10 I receive the following error:  E: Repository 'http://ppa.launchpad.net/ondrej/php/ubuntu artful InRelease' changed its 'Label' value from '***** The main PPA for PHP (5.6, 7.0, 7.1) with many PECL extensions *****' to '***** The main PPA for supported PHP versions with many PECL extensions *****' N: This must be accepted explicitly before updates for this repository can be applied. See apt-secure(8) manpage for details."   The man page doesn't really point to a solution.  My question is, how do I explicitly accept the change? In chapter 1, of Landau-Lifshitz Mechanics' book, Landau through isotropy and homogeneity of space and homogeneity of time proves that the Lagrangian must depend of magnitude of velocity of the particle.  This seemed fine. But he didn't give a reason as to why it must depend of $|v|^2$ and not on some $|v|^n$ where $n\neq2$. Difference between shadowing and overriding in C#? How to Sort a 2D array? I was wondering about the reason of the choose of the X as symbol used to represents the "Close application" operation. Correct usage of "lest" Which of the followings is/are the correct usage of the word "lest"? How are these different from each other?   ...hesitant to speak out lest he be fired. ...hesitant to speak out lest he'd be fired. ...hesitant to speak out lest he would/will be fired.   P.S. I took point number 1 as the reference for this question from the definition of lest from the Merriam-Webster Dictionary. What do I do when glitched? I was playing Grand Theft Auto Online on Xbox 360, and a player teleported to me.  I shot them, but they placed a campfire on me.  Now, I am constantly being burnt to death. How do I get out? Negation in English How did Vader saving Luke turn him to the good side? Couldn't Vader save his son and continue being a Sith Lord? Couldn't he have let Luke go and basically become the Emperor and have the Galaxy to himself? I don't think killing the Emperor to save your son will automatically convert you to the light side. Enlighten me. Impact of denied entry to Croatia on trying to enter a Schengen country with a valid visa Why are mathematical proofs that rely on computers controversial? There are many theorems in mathematics that have been proved with the assistance of computers, take the famous  for example. Such proofs are often controversial among some mathematicians. Why is it so?  I my opinion, shifting from manual proofs to computer-assisted proofs is a giant leap forward for mathematics. Other fields of science rely on it heavily. Physics experiments are simulated in computers. Chemical reactions are simulated in supercomputers. Even evolution can be simulated in an advanced enough computer. All of this can help us understand these phenomena better.   But why are mathematicians so reluctant? What is the benefit of breaking up a continuous predictor variable? I'm wondering what the value is in taking a continuous predictor variable and breaking it up (e.g., into quintiles), before using it in a model.   It seems to me that by binning the variable we lose information.   Is this just so we can model non-linear effects?  If we kept the variable continuous and it wasn't really a straight linear relationship would we need to come up with some kind of curve to best fit the data? Is there any general and systematic way of reducing the higher order linear ODE to a system of first order ODE?  For example, assume we have $a_3x^{(3)}+a_2x^{(2)}+a_1x^{(1)}+a_0x=0$, then how do we convert this into matrix form(a system of first order ODE). And after we solve the system of equation, how to combine them into our final solution $x(t)$?  Thanks for helping me out! Are there cheap GPS or other navigator devices with downloadable maps for the whole world? I don't need a recommendation or a list but my knowledge of GPS and "navi"s and the differences between them is an utter mystery to me.  But often I'm lost in backstreets in random countries where access to something like a live Google Maps would be awesome. I absolutely cannot afford a smartphone with worldwide roaming though.  Can GPS's do what I want or am I barking up the wrong tree? If they can is it only high end ones than can? How to quickly move one layer to a different group in large Photoshop files, without dragging? What book has criminals wear a ring? I remember reading one of my father's books when I was younger.  It was about a guy who ended up getting in trouble with the law and was required to wear a ring that could not be removed and would shock the wearer any time they committed a crime (No matter how minor.)    The book was probably published in the early to mid 80s.  I thought the name of the book was 'The Ring', but I am unable to locate anything.  The cover had a car with a single wheel driving on a metal I-beam. I am running a query like   select id from students where school_id='67153fb1-8f79-441d-a747-ca3778cf6d3d';   on table that looks like                                      Table "public.students"           Column       |            Type             |             Modifiers                   -------------------+-----------------------------+------------------------------------      id                | uuid                        | not null default gen_random_uuid()      school_id        | uuid                        |  Indexes:     "students_pkey" PRIMARY KEY, btree (id)     "students_school_id_idx" btree (school_id)   The query plan for the select statement with just where looks like below-  explain select id from students where school_id='67153fb1-8f79-441d-a747-ca3778cf6d3d';                                             QUERY PLAN                                             --------------------------------------------------------------------------------------------------  Bitmap Heap Scan on students  (cost=581.83..83357.10 rows=24954 width=16)    Recheck Cond: (school_id = '67153fb1-8f79-441d-a747-ca3778cf6d3d'::uuid)    -&gt;  Bitmap Index Scan on students_school_id_idx  (cost=0.00..575.59 rows=24954 width=0)          Index Cond: (school_id = '67153fb1-8f79-441d-a747-ca3778cf6d3d'::uuid)   This is fairly fast.  Now we add order by to the query with id that degrades the query.(Such a query is generated by Rails like student.first with some condition)  explain select id from students where school_id='67153fb1-8f79-441d-a747-ca3778cf6d3d' order by id asc limit 1;                                                  QUERY PLAN                                                  ------------------------------------------------------------------------------------------------------------  Limit  (cost=0.43..488.51 rows=1 width=16)    -&gt;  Index Scan using students_pkey on students  (cost=0.43..12179370.22 rows=24954 width=16)          Filter: (school_id = '67153fb1-8f79-441d-a747-ca3778cf6d3d'::uuid)   How can I improve the speed to return the results of this query? Currently there are around 4990731 records in the table and is taking more than 2 minutes! Its running on RDS with db.t2.medium instance.  UPDATE After running Analyze students;  explain select id from students where school_id='67153fb1-8f79-441d-a747-ca3778cf6d3d' order by id asc limit 1;                                                        QUERY PLAN                                                         -----------------------------------------------------------------------------------------------------------------      Limit  (cost=8.46..8.46 rows=1 width=16)        -&gt;  Sort  (cost=8.46..8.46 rows=1 width=16)              Sort Key: id              -&gt;  Index Scan using students_school_id_idx on students  (cost=0.43..8.45 rows=1 width=16)                    Index Cond: (school_id = '67153fb1-8f79-441d-a747-ca3778cf6d3d'::uuid)      explain analyze select id from students where school_id='67153fb1-8f79-441d-a747-ca3778cf6d3d' order by id asc limit 1;                                                                           QUERY PLAN                                                                              -----------------------------------------------------------------------------------------------------------------------------------------------------------     Limit  (cost=8.46..8.46 rows=1 width=16) (actual time=1.853..1.855 rows=1 loops=1)      -&gt;  Sort  (cost=8.46..8.46 rows=1 width=16) (actual time=1.851..1.852 rows=1 loops=1)            Sort Key: id            Sort Method: quicksort  Memory: 25kB            -&gt;  Index Scan using students_school_id_idx on students  (cost=0.43..8.45 rows=1 width=16) (actual time=1.841..1.843 rows=1 loops=1)                  Index Cond: (school_id = '67153fb1-8f79-441d-a747-ca3778cf6d3d'::uuid)     Planning time: 0.145 ms     Execution time: 1.874 ms Tree level QFT and classical fields/particles To better describe the above problem, whenever I start up my Ubuntu/Windows 10 Machine and select Ubuntu, whenever the machine tries to start the GNOME Desktop Environment, it says it started it successfully. however, I never get a graphical desktop environment to use. I can fix this by logging into tty3 and typing gnome-session but I don't really want to do that as, for some reason, that skips login. Can anyone help? "many a time" means "many times"?