i had installed windows 7(32 bit) and Ubuntu. It was working fine, but after that I installed Windows 8 (64 bit) instead of Windows 7. Now I'm unable to boot Ubuntu.  Please help me to open my previous Ubuntu and how I'll get my data which were inside Ubuntu.
I installed Windows 7, which ate Ubuntu's boot file. When starting up the computer, it now goes straight to Windows, without giving me the option of booting Ubuntu.   How can I get Ubuntu back?
Does Airplane Mode allow GPS location to pass through? This is what I saw when my plane was taxing to the runway at CDG:     Airplane mode was on and all other transmissions (except Location), including WiFi, mobile data, NFC and Bluetooth were off.  Location was not manually turned on by me, after I enabled Airplane Mode. It remained turned on.  What am I missing? Is GPS now so widely accepted on-board planes that Android changed its configuration to let this kind of signal/communication to pass through Airplane mode "block"?  I believe that  isn't a duplicate, because at that time (2016) Location was generally "included" in Airplane mode and was turned off by enabling it. Bump right-aligned text to next line iff no room Find a closed form of the series $\sum_{n=0}^{\infty} n^2x^n$ The question I've been given is this:  Using both sides of this equation:  $$\frac{1}{1-x} = \sum_{n=0}^{\infty}x^n$$  Find an expression for $$\sum_{n=0}^{\infty} n^2x^n$$ Then use that to find an expression for $$\sum_{n=0}^{\infty}\frac{n^2}{2^n}$$  This is as close as I've gotten:  \begin{align*} \frac{1}{1-x} &amp; = \sum_{n=0}^{\infty} x^n \\ \frac{-2}{(x-1)^3} &amp; = \frac{d^2}{dx^2} \sum_{n=0}^{\infty} x^n \\ \frac{-2}{(x-1)^3} &amp; = \sum_{n=2}^{\infty} n(n-1)x^{n-2} \\ \frac{-2x(x+1)}{(x-1)^3} &amp; = \sum_{n=0}^{\infty} n(n-1)\frac{x^n}{x}(x+1) \\ \frac{-2x(x+1)}{(x-1)^3} &amp; = \sum_{n=0}^{\infty} (n^2x + n^2 - nx - n)\frac{x^n}{x} \\ \frac{-2x(x+1)}{(x-1)^3} &amp; = \sum_{n=0}^{\infty} n^2x^n + n^2\frac{x^n}{x} - nx^n - n\frac{x^n}{x} \\ \end{align*}  Any help is appreciated, thanks :) Inaccurate shading on object When can I make opportunity attacks? Does a subsequent charm effect override a previous one? In a recent session, I was confused about how multiple charm effects would interact with each other:  A vampire used its 'Charm' ability to charm a PC. It reads (paraphrased):     The target must succeed on a saving throw or be charmed by the vampire. It takes the vampire's requests in the most favourable way it can. It can repeat the saving throw if the vampire or its companions harm it. Otherwise, the effect last 24 hours or until the vampire is destroyed, is on another plane of existence, or takes a bonus action to end the effect.   Another PC then decided to attempt to wrest control back from the vampire by casting crown of madness on their friend. it reads (paraphrased):     The creature must succeed on a saving throw or be charmed. The charmed target must use its action before moving on each of its turn to make a melee attack against a creature other than itself that you mentally choose. The target can act normally on its turn if you choose no creature, or none are within its reach.   At the time, I ruled that both effects would take place simultaneously. This meant that Crown of Madness took effect first, and the vampire's charm afterwards.  Was this the correct ruling? Can a creature be charmed twice? Or does one charm effect override the other? $C^1[a,b]$ is closed in $C[a,b]$ Prove the inequality $\frac{a}{c+a-b}+\frac{b}{a+b-c}+\frac{c}{b+c-a}\ge{3}$ Using nohup to keep a script running indefinitely I am very new to Linux and I've only been using it to SSH to my web server using Putty. The issue I am having is this:  Basically I've got 2 php scripts. One get_tweets.php constantly listens for tweets on twitters Streaming API whilst the other - parse_tweets.php logs these into a db. In order for these to work they've to be kept running continuously.   I've been using the following commands to run them in the background and from what I've seen they run for most of the day, however whenever I log on to my computer in the morning the scripts have stopped and I've to run commands again.  nohup php my_script.php &gt; /dev/null &amp;   I'm just wondering if that is normal based on the commands I am using, should they run indefinitely when using nohup and if not what is the alternative? A CRON job?  Thanks for the help Shapefile layer no longer editable (toggle edit option greyed out) in QGIS Using memory with a higher MHz rating? Can MacBook Pro's successfully support and fully exploit RAM of a higher MHz rating than that which they ship with?    For example, take my 15" MacBook Pro () that ships with 4GB of 1333MHz DDR3 memory. I'm considering buying 16GB of the same clock speed even though Apple says that it can "support up to 8GB" — .  What about installing 1600MHz in the 16GB variant — will it work? Or will it be clocked down to 1333MHz? When compared to 16GB 1333MHz, will the higher clock speed improve battery life, performance, timings, or what? In an exercise in Atiyah-Macdonald it asks to prove that the prime spectrum $\operatorname{Spec}(A)$ of a commutative ring $A$ as a topological space $X$ (with the Zariski Topology) is compact.   Now because the basic open sets $X_f = \{\mathfrak{p} \in \operatorname{Spec} (A) : \{f\} \not\subseteq \mathfrak{p} \}$ form a basis for the Zariski Topology it suffices to consider the case when   $$X = \bigcup_{i \in I} X_{f_i}$$   where $I$ is some index set. Then taking the complement on both sides we get that   $$\emptyset = \bigcap_{i \in I} X_{f_i}^c$$  so there is no prime ideal $\mathfrak{p}$ of $A$ such that all the $f_i$'s are in $\mathfrak{p}$. Now from here I am able to show that the ideal generated by the $f_i$'s is the whole ring as follows. Since there is no prime ideal $\mathfrak{p}$ such that all the $f_i \in \mathfrak{p}$, it is clear that there is no $\mathfrak{p}$ such that $(f_i) \subseteq \mathfrak{p}$ for all $i \in I.$ Taking a sum over all the $i$ then gives $$\sum_{i \in I} (f_i) = (1).$$  Now here's the problem:          How do I show from here that there is an equation of the form $1 = \sum_{i \in J} f_ig_i,$ where $g_i \in A$ and $J$ some finite subset of $I$?       This part has been giving me a headache. I am not sure if the finiteness bit has to do with algebra, topology or the fact that we are dealing with prime ideals.  This is not a homework problem but rather for self-study.  $\textbf{Edit:}$ I have posted my answer below after the discussion with Dylan and Pierre. Finite groups with exactly one maximal subgroup Pre-image of a measurable set A is always measurable? My keyboard doesn't have an Fn key so I can't get the coordinates to show up. I don't know how to get into the multiplayer settings and Shift + F3 doesn't work either.  How can I fix this? try+gerund/infinitive (Difference in meaning) I tried to open the door. I tried opening the door   We can use both infinitive and gerund with verb "try" as used in above sentences. Does it change the meaning of the  sentence if use gerund or infinitive?.(here i don't know if the meaning of sentences is changed.)     The same confusion arise in these two sentences.  1.I stopped seeing him. 2. I stopped to see him.(But in case of these two sentence i know the meaning is changed but don't know exactly what the change is). The responsiveness is really bad on a newly installed Ubuntu 14.04 LTS.  Here's the specs of my laptop:  Quadcore Intel i7-4600U CPU @ 2.10GHz 12GB Ram 1TB Samsung EVO SSD   And when gradle is compiling, my entire system slows to a crawl, videos begin stuttering, browser scrolling lags... etc.  The same goes when a page refresh occurs in another window in Chrome, and while it refreshes, the HTML5 video in another tab begins stuttering.  How can I fix this?  Here are some logs:  $ vmstat -a 1 5 -   $ iostat -x 1 5 -   $ top -b - I let him do it.   and     I allow him to do it.   Why does the latter require to?  What are the "rules" of using to with an infinitive? When is it necessary? The title of  of  is, "Is it posible [sic]?"  This doesn't provide any information at all. It should be mandatory for everyone asking questions on the Internet to read , which says:     Help your community learn from the question. When you field a good question, ask yourself "How would the relevant documentation or FAQ have to change so that nobody has to answer this again?" Is it possible to create a list of all the figures at the end of a document (this I can do) and make it appear in the table of contents?  So in the the table of content there will be a line saying List of figures ... 19 for example?