Instant messaging apps are gaining more and more popularity all over the world. IMO is one of the chat apps available on the modern mobile app market. However, like any other technology means, the app may have some problems. Users find it particularly helpful for those who use many different communications channels with many different people. So, one of the main issues associated with IMO has to do with its operation on several iPhone models, such as iPhone 6s plus, and iPhone 5s.
What these users usually do in such cases is to turn to Apple Support. However, IMO is a third party app. So, you need to address the problem with the developer. IMO users reported another important issue in Another similar issue was registered in The video calling problem is another concern discussed by IMO users. Particularly, the problem has to do with the voice of video calls. As users note, the problem still exists after they reinstall the app.
Basically, the most common IMO problems that users report include the following:. You can simply find an alternative and enjoy it. IMO not working? What about Pinngle? This is a free instant messaging IM app. You can use it both on Android and iOS devices. You can be sure to use Pinngle even in the remote corners of the world. Just read below to learn about other advantages that Pinngle offers to its users. This chat app is almost impossible to block or shut down.
Pinngle is an end-to-end E2EE encrypted messaging app. What is more important, this chat app never keeps any personal data on its servers. So, your most sensitive information will never be available to any third party.
With Pinngle, you can enjoy the top quality. Pinngle uses less data as compared to other options. You can enjoy quality voice and video calling even with the slowest internet. Do you have almost no internet connection? Consider purchasing international or virtual numbers through Pinngle.Any help is most welcome. If you want to provide problems, we are particularly interested in those on a dark background.
We are generally very happy to receive national contests that are not yet offered on the site such as those in other countriesalthough it may be a good idea to contact us first - some such contests are already waiting in a stack.
The materials you send us should be in one of the following forms in the order of preference :. Your help will be duly acknowledged, and your contribution will probably appear on the site in as soon as one week! One more thing: Statistically, in such a large set of problems some mistakes must occur.
We try to reduce their number to a minimum. If you encounter any for example, a senseless or wrong problem, a language mistake, a typo, etc. Problems from Olympiads At this moment the archive contains problems. The materials you send us should be in one of the following forms in the order of preference : A LaTeX file in English; A file of any type in English; A file in another language, if necessary: the major European languages and all Slavic languages are OK.
Cze-Pol-Slk Match. National Competitions The collection contains problems from the following 44 countries: Austria.
FEATURE: The Growing Problem of IMO 2020 VLSFO Bunkers With Marginally Off-Spec Sulfur
Czech Rep. Hong Kong. Macedonia, FYR. The Netherlands. South Korea.He is currently studying Mathematics in Cambridge University. The following post presents his insights in solving an MO problem. While I draw my examples mainly from problems in number theory, the strategies I mention are very general and apply to most Olympiad problems. The opinions expressed in this post are entirely mine, and I accept that everyone has a different way of approaching problems.
I may talk about more specific techniques in a separate post later. There is no shortcut to become really good at solving math Olympiad problems. He spends an average of several hours a day often up to 4 or 5 hours solving Olympiad problems.
Over time, these hours put into solving problems will help you amass a huge vocabulary of Olympiad tricks, techniques, theorems and lemmas, and hone your problem solving intuition. Doing math Olympiad is very much like playing soccer. While a soccer match only lasts for 90 minutes, it is what happens before the match that truly decides the game — the hours put into training daily to gain incredible agility, stamina, and an impeccable technique.
Of course, the strategies adopted during the minute match are also important, but never as crucial as the training and preparation that comes before it. Fitness and skill comes with practice, and practice makes perfect.
A good Olympiad problem is one that uses very elementary techniques in very clever ways. It should not require the use of any very advanced math theorems, beyond the usual handful e. There was an earlier post by Shi Jie that touches on these refer to the links abovewhich I feel is a fairly comprehensive list and you should make sure you already know most of these by heart.
These simple techniques go a very long way. Practically all SMO problems can be solved using elementary methods and, occasionally, one or two basic theorems. You would first try to change or simplify the problem if possible, try small cases, then pick an approach, try to prove it and maybe fail, pick another approach or maybe try to prove a stronger result that you conjectured, find out that your conjecture was false, move on to another approach, etc.
If you have tried enough Olympiad problems, you should be familiar with common tricks and techniques for particular topics, and you will be able to use these as a starting point for approaching problems.
Pre-match preparation: Theorems, Lemmas, Techniques. It is a good habit to first find easy solutions like. The fact that a solution exists already eliminates some possible approaches like using modular arithmetic to prove the no solutions exist.It has since been held annually, except in The content ranges from extremely difficult algebra and pre-calculus problems to problems on branches of mathematics not conventionally covered at school and often not at university level either, such as projective and complex geometryfunctional equationscombinatoricsand well-grounded number theoryof which extensive knowledge of theorems is required.
Calculus, though allowed in solutions, is never required, as there is a principle that anyone with a basic understanding of mathematics should understand the problems, even if the solutions require a great deal more knowledge. Supporters of this principle claim that this allows more universality and creates an incentive to find elegant, deceptively simple-looking problems which nevertheless require a certain level of ingenuity.
The selection process differs by country, but it often consists of a series of tests which admit fewer students at each progressing test. Teams are not officially recognized—all scores are given only to individual contestants, but team scoring is unofficially compared more than individual scores. Subject to these conditions, an individual may participate any number of times in the IMO. The International Mathematical Olympiad is one of the most prestigious mathematical competitions in the world.
The first IMO was held in Romania in Since then it has been held every year except in That year, it was cancelled due to internal strife in Mongolia. Sources differ about the cities hosting some of the early IMOs.
This may be partly because leaders are generally housed well away from the students, and partly because after the competition the students did not always stay based in one city for the rest of the IMO. Several former participants have won awards such as the Fields Medal. The competition consists of six problems.
Each problem is worth seven points for a maximum total score of 42 points. No calculators are allowed. The competition is held over two consecutive days; each day the contestants have four-and-a-half hours to solve three problems. The problems chosen are from various areas of secondary school mathematics, broadly classifiable as geometrynumber theoryalgebraand combinatorics.
They require no knowledge of higher mathematics such as calculus and analysisand solutions are often short and elementary.
However, they are usually disguised so as to make the solutions difficult. Prominently featured are algebraic inequalitiescomplex numbersand construction -oriented geometrical problems, though in recent years the latter has not been as popular as before. Each participating country, other than the host country, may submit suggested problems to a Problem Selection Committee provided by the host country, which reduces the submitted problems to a shortlist.
IMO Not Working? Look What You Can Do
The team leaders arrive at the IMO a few days in advance of the contestants and form the IMO Jury which is responsible for all the formal decisions relating to the contest, starting with selecting the six problems from the shortlist. As the leaders know the problems in advance of the contestants, they are kept strictly separated and observed.
Each country's marks are agreed between that country's leader and deputy leader and coordinators provided by the host country the leader of the team whose country submitted the problem in the case of the marks of the host countrysubject to the decisions of the chief coordinator and ultimately a jury if any disputes cannot be resolved.This problem seems hard, then it doesn't, but it really is
The selection process for the IMO varies greatly by country. In some countries, especially those in East Asiathe selection process involves several tests of a difficulty comparable to the IMO itself.
For high scorers in the final competition for the team selection, there also is a summer camplike that of China. In countries of the former Soviet Union and other eastern European countries, a team has in the past been chosen several years beforehand, and they are given special training specifically for the event.
However, such methods have been discontinued in some countries. While identifying the winners, only the results of the current selection olympiads are considered. The participants are ranked based on their individual scores. Medals are awarded to the highest ranked participants; slightly fewer than half of them receive a medal. The cutoffs minimum scores required to receive a gold, silver or bronze medal respectively are then chosen so that the numbers of gold, silver and bronze medals awarded are approximately in the ratios Participants who do not win a medal but who score seven points on at least one problem receive an honorable mention.
Special prizes may be awarded for solutions of outstanding elegance or involving good generalisations of a problem.
This last happened in Nikolay Nikolov, Bulgaria and Iurie Boreicobut was more frequent up to the early s. The rule that at most half the contestants win a medal is sometimes broken if it would cause the total number of medals to deviate too much from half the number of contestants. This last happened in when the choice was to give either Account Options Sign in.
Top charts. New releases. Add to Wishlist. Send text or voice messages or video call with your friends and family easily and quickly, even the signal under bad network.
Enjoy live talks with friends, create a conference room up to 6 members, and send large size videos or documents as you like.
It is the perfect tool for throwing an online party or working from home. Teachers can create a group, go live and have an online class anytime and anywhere. Enjoy live stream with up to group members!
More interesting interaction with gifts sending, stickers and emoji. Online classes can be full of fun! Avoid SMS and phone call charges, no fees or subscription for every message or call. PDF, etc. No extra charge to send international messages. You can see all your messages, calls and share other media directly from your desktop or Android tablet.
You can also get all kinds of latest resources from imo. You will never miss any notifications or messages even if you close the app! Contact your provider for details. Reviews Review Policy.
View details. Flag as inappropriate. Visit website. See more. Viber Media S. Enjoy the most secure messaging, video chat and free calls around the world! Messenger — Text and Video Chat for Free.
Free group video chat, video calls, voice calls and text messaging. Algento Cloud Computing Limited. LLC Mail. Join in! Baby Penguin.One of the main problems shipping has had with the new 0. Any subsequent claim by the buyer arguing that the fuel was off-specification would have little chance of succeeding.
With the cases that fall in that crack between 0. And there seem to be a lot of these cases emerging. Staal pointed out that within a cargo of 0. If the ship's test result is above that threshold A large bunker buyer in Northwest Europe and the Mediterranean said they usually would submit a claim when they discover fuel to be off-specification, but there have been cases when they have taken product that they found to be marginally over 0.
The main problem lies with how port state control authorities PSCs interpret the law, and how aggressive they decide to be in enforcing it. Some may be inclined to be lenient in these cases -- after all, there's unlikely to be any significant financial advantage in buying a 0.
But it's also possible that some authorities will be keen to appear vigilant right from the start of the new sulfur limit this year, and will go after even marginal infractions aggressively as a statement of intent to the shipping industry.
PSCs should be more forgiving in the early stages of the 0. The type of punishment the PSCs choose is key to how disruptive these cases can be for shipowners. Fines for these marginal cases would be an irritant, but unlikely to cause significant financial problems. The delays involved in undergoing debunkering, however -- where a ship is forced to return to port, remove all the non-compliant fuel from its tanks and take on more fuel before being allowed to leave -- are far more of a threat.
When the sulfur limit in the emission control areas ECAs was lowered to 0. Sulfur is currently the only parameter where IMO has placed a limit beyond which the fuel may not be consumed. The previous sulfur cap of 3. Sulfur limit violations were therefore limited to the ECAs, where the limit is set to 0. With the global 0. Tolson says clarity on the matter is needed for the sake of both suppliers and buyers, and has made addressing the matter part of his platform in the upcoming Ibia election.
Now we see downside," he added. What it does not do though is protect you from reputational damage if you are one of the first companies to be caught with 'off-spec' product.
This is the other big problem for shipowners -- quite apart from any legal concerns, the reputational risk of being labelled a 'sulfur cheat' could be a considerable threat to their companies. The earliest cases of non-compliance announced by the PSCs are likely to receive widespread attention in the media, even for minor infractions.
Cruise lines and the largest publicly traded container shipping companies are particularly sensitive to reputational impacts, and these companies may be best advised to stick with marine gasoil for now, or to insist on VLSFO blends tested by the supplier at 0. Ultimately, while these cases will be a recurring headache in the first six months of this year, this is a problem that should resolve itself over time.
No-one is deliberately producing or supplying 0. This is a problem largely caused by the HSFO residue left in all the pipes, barges and fuel tanks that the new VLSFO blends are touching before they reach ships' engines.
That residue is leaving fuels tested earlier at 0. Bjarke Staal at BMS said his company has already observed a decline in the number of marginal sulfur disputes this year as delivery infrastructure is cleaned and refineries improve their blending recipes and production lines. If PSCs can resist the urge to prosecute shipowners aggressively for the first few months of this year, the industry will be able to get through the worst of this situation relatively unscathed.
He is an experienced financial editor and reporter with a first-class degree in Arabic and Russian, a postgraduate diploma in newspaper journalism and several years' history of covering the oil and shipping industries and capital markets.To browse Academia. Skip to main content. Log In Sign Up. Matthew Ng. It has played a significant role in generating wide interest in mathematics among high school students, as well as identifying talent.
In the beginning, the IMO was a much smaller competition than it is today. Since then, the competition has been held annually. Gradually, other Eastern-block countries, countries from Western Europe, and ultimately numerous countries from around the world and every continent joined in. The only year in which the IMO was not held waswhen for financial reasons no one stepped in to host it. Today this is hardly a problem, and hosts are lined up several years in advance.
In the 45th IMO, held in Athens, no fewer than 85 countries took part. The Competition The format of the competition quickly became stable and unchanging. Each country may send up to six contestants and each contestant competes individually without any help or collaboration.
The country also sends a team leader, who participates in problem selection and is thus isolated from the rest of the team until the end of the competition, and a deputy leader, who looks after the contestants. The IMO competition lasts two days. On each day students are given four and a half hours to solve three problems, for a total of six problems. The first problem is usually the easiest on each day and the last problem the hardest, though there have been many notable exceptions. IMO is one of the most difficult problems from all the Olympiads, having been fully solved by only six students out of several hundred!
Each problem is worth 7 points, making 42 points the maximum possible score. The number of points obtained by a contestant on each problem is the result of intense negotiations and, ultimately, agreement among the problem coordinators, assigned by the host country, and the team leader and deputy, who defend the interests of their contestants. This system ensures a relatively objective grade that is seldom off by more than two or three points.
Awards Though countries naturally compare each other's scores, only individual prizes, namely medals and honorable mentions, are awarded on the IMO. Fewer than one twelfth of participants are awarded the gold medal, fewer than one fourth are awarded the gold or silver medal, and fewer than one half are awarded the gold, silver or bronze medal. Among the students not awarded a medal, those who score 7 points on at least one problem are awarded an honorable mention.
This system of determining awards works rather well. It ensures, on the one hand, strict criteria and appropriate recognition for each level of performance, giving every contestant something to strive for.
On the other hand, it also ensures a good degree of generosity that does not greatly depend on the variable difficulty of the problems proposed. How the problems are selected The selection of the problems consists of several steps. Participant countries send their proposals, which are supposed to be novel, to the IMO organizers.
The organizing country does not propose problems. From the received proposals the so-called longlisted problemsthe Problem Committee selects a shorter list the so- called shortlisted problemswhich is presented to the IMO Jury, consisting of all the team leaders. From the short-listed problems the Jury chooses 6 problems for the IMO. Apart from its mathematical and competitive side, the IMO is also a very large social event.
After their work is done, the students have three days to enjoy the events and excursions organized by the host country, as well as to interact and socialize with IMO participants from around the world. All this makes for a truly memorable experience. Let a, b, c be real numbers. Using the numbers a, b, c, form a quadratic equation in cos 2x, whose roots are the same as those of the original equation.
Construct a right triangle with given hypotenuse c such that the median drawn to the hypotenuse is the geometric mean of the two legs of the triangle. An arbitrary point M is selected in the interior of the segment AB.
The circles circum- scribed about these squares, with centers P and Q, intersect at M and also at another point N.