How to restore Windows as a boot option in Grub
Unable to boot into Windows after installing Ubuntu, how to fix?
Can't update drupal core to 7.27 How do i know which wheels will fit my bike? my bike is:  and everything I have came with the bike, only now the axle of the rear wheel bent and the skewer has lost its grooves.  and I would like to replace the rear wheel with the 12 x 142mm version of:   I want to reuse the old casettes and disc break. I was told to buy new rotor bolts, will these do?   Will I be able to migrate all my previous parts onto this new wheel and will the wheel fit onto my bike?  update: A replacement axle would be prefered. What axle would work for my bike? Forgotten PostgreSQL Windows password Arguments for/against same birthday for siblings? My son is born on October 1st three years ago. My wife is pregnant again and the calculated delivery date is October 22nd. Both children are boys, 3 years apart. We might end in a situation where the delivery is earlier, for reasons irrelevant to this question.   I believe that around their birthdays is the only time in the whole year that the actual date matters. It really does boil down to practical considerations around patience (gifts) and planning. I think that if there is, say, a week or more between the birthdays then it's easy to separate but if the difference is only a very few days then it gets complicated, and that's the situation I'd like to avoid.  I know from friends that having the same birthday makes events easier to plan, from the parents' perspective. It would also remove the unhappiness of a small child saying "why does he get presents today and I don't." Being a twin, and married to one, I know that there's nothing problematic in sharing a birthday as long as both get their fair share of attention.    What are practical arguments for, and against, choosing the same birthday for the second child? What considerations apply when the second child's birthday is only a very few days after the elder sibling's? How to check if a macro value is empty or will not create text with plain TeX conditionals? I have a macro which holds some text value, e.g. \macro{some text}. If it is empty, I would like for nothing to appear in the document, but it has some content of any kind which would produce text displayed in the document, I would like a message to appear, "Text: some text".   \macro{} would be considered empty. \def\somedata{}, \macro{\somedata} would be considered empty. \macro{0} would be considered not empty.   I have tried making a TeX conditional which can check if the value is not empty, but nothing I tried works, e.g.:  \ifx #1 {} \else     Text: #1 \fi  \ifx#1{} \else     Text: #1 \fi  \ifx #1 \nil \else     Text: #1 \fi  \ifx#1!="" \else     Text: #1 \fi   What is the correct syntax for creating a conditional in plain TeX with checks if a value is not empty? I am new to Stack Exchange. I know there is a lot of discussion sites for Stack Exchange. I would like to know about there were any Stack Exchange site available for discussing and solving personal psychological problems. Should I keep my swap file on an SSD drive? I'm considering getting an SSD drive to run as the primary OS partition.  As I understand, this should provide a substantial improvement in performance.     My question is this: Should I leave the swap file on that drive?     The swap partition will be largely random seeks and so should benefit from the speed.  On the other hand, it will be constantly written to which will wear out the drive faster. Tried to install both Windows and Ubuntu, now neither will boot I have dual US and UK citizenship, but the US citizenship has only just been realized (wasn't aware I had claim to US citizenship earlier).  Unfortunately I haven't received my US passport yet. Can I still travel to the US only using my UK passport?  I understand that the US does require citizens to travel on a US passport, but would they even know that I am a dual citizen if I've only ever traveled on my UK passport? (Especially considering that my US passport has never been used before in any form - as I haven't received it).  If I was only entering the US for a small trip,  would it show on the screen that I also have US citizenship when they scan my UK passport? Run a GUI program at startup I am using Ubuntu 14.04. I wrote a small script named trial. The contents of the script are as follows:   #!/bin/sh SHELL=/bin/sh PATH=/bin:/sbin:/usr/bin:/usr/sbin      sh -c firefox   I copied the script to /etc/init.d, modified permission using chmod +x trial and used update-rc.d trial defaults. The file made link but when I rebooted the machine. It did not run firefox. I tried cron @reboot but with no success. I tried rc.local too again failure. On some Microsoft Access queries, I get the following message:  Operation must use an updatable query. (Error 3073).  I work around it by using temporary tables, but I'm wondering if there's a better way.  All the tables involved have a primary key. Here's the code:  UPDATE CLOG SET CLOG.NEXTDUE = (     SELECT H1.paidthru      FROM CTRHIST as H1     WHERE H1.ACCT = clog.ACCT AND     H1.SEQNO = (         SELECT MAX(SEQNO)          FROM CTRHIST          WHERE CTRHIST.ACCT = Clog.ACCT AND          CTRHIST.AMTPAID &gt; 0 AND         CTRHIST.DATEPAID &lt; CLOG.UPDATED_ON     ) ) WHERE CLOG.NEXTDUE IS NULL; What is the difference between equation and formula? Sometimes equation and formula are used interchangeably, but I was wondering if there is a difference.  For example, suppose we can calculate a car's fuel efficiency as:  mpg = distance traveled in miles / the fuel used in a gallon   Is that an equation or formula? Expectation values of the position operator is equal to zero in case of even potentials? How to deal a specific amount of damage using commands? I want to make a datapack where if you touch lime glass, you get damaged 2.5 hearts. I don't want the commands to work for just this specific value. Instead, I want to be able to specify the amount of damage. I can't use the instant damage effect because it's not controllable. The  spell says time stops for other creatures.  What all is affected by the spell? Is gravity affected? Air movement?  I know that the spell only does what it says, and nothing else, but just wondering.   In addition, is it saying that the other creatures are not affected by environmental effects and the like while time is stopped?  For instance, if a wind blew really hard at one of the creatures you're fighting, would it affect that foe while time stop is active? If you were to place a bear trap behind the person, and a hard wind blew enough to tip them, would they then fall over onto the bear trap and be damaged without the spell ending?  This is a very curious spell... Show that $\mathbb{Q}\times \mathbb{Q}$ is denumerable Uniform continuity of $f(x) = x \sin{\frac{1}{x}}$ for $x \neq 0$ and $f(0) = 0.$ The parmesan cheese in pasta recipe is quite expensive.....do we have cheaper alternative??  Are there are cheddar cheese which can replace parmesan cheese? Ubuntu 14.10 folder icons missing Average length of the longest segment This post is related to a previous SE post  concerning average length of a smallest segment.  A rope of 1m is divided into three pieces by two random points. Find the average length of the largest segment. My answer is 11/18.  Here is how I do it:  Here we have two independent random variables $X,Y$, both uniform on $[0,1]$. Let  $A=\min (X,Y), B=\max (X,Y)$ and $C=\max (A, 1-B, B-A)$. First we want to find the probability density function $f_C(a)$ of $C$. Let $F_C(a)$ be the cumulative distribution function. Then $$ F_C(a) = P(C\le a)=P(A\le a, 1-B\le a, B-A\le a).$$  By rewriting this probability as area in the unit square, I get $$F_C(a)=\left\{\begin{array}{ll} (3a-1)^2 &amp; \frac{1}{3}\le a\le \frac{1}{2}\\ 1-3(1-a)^2 &amp; \frac{1}{2}\le a\le 1\end{array}\right.$$ from which it follows that  $$f_C(a)=\left\{\begin{array}{ll} 6(3a-1) &amp; \frac{1}{3}\le a\le \frac{1}{2}\\ 6(1-a) &amp; \frac{1}{2}\le a\le 1\end{array}\right.$$ Therefore the expected value of $C$ is $$\int_{1/3} ^{1/2}6a(3a-1) da+\int_{1/2} ^{1}6a(1-a) da= \frac{11}{18}.$$  My questions are:  (A) Is there a "clever" way to figure out this number 11/18?  (B) What is the answer if the rope is divided into $n&gt;3$ segments?