I spent half a year studying the GRE prep books Manhattan, all of Princeton GRE prep, all Greg Mat prep, all this trash has nothing to with what is actually on the new tests, I got almost no problems at all that resembled anything, despite literally doing thousands and thousands of pages and spending hundreds and hundreds of hours, and my quant score is the exact same as when I didn't study at all. I would say, this whole industry is a fraud, only use the ETS books I guess, because that's apparently how the scam works. Only they know what is going to actually be on the test, these other guys are making up problems. I assume ETS re-designs the test constantly so you have to buy their prep material only, and they extort people to keep them from getting into industries without paying them for the answers basically. What a waste of my life.

I really feel defeated, I have the GRE scheduled for mid January but I haven’t had much time to study. I’m a full time student, volunteer, work, and have been working on grad admission applications. All while doing this I find the time to be human and spend time with friend, family, and my significant other. I keep avoiding studying because I’m just so overwhelmed with everything else and in turn it makes me so anxious and I get so exhausted by the afternoon. When I do study I’m only able to get a little bit of work in because I have so many other work and school obligations. I just want to give up, I’m really anxious.

I've been pretty burnt out at my current job teaching high school and have always dreamed of finishing up some sort of grad school program and moving up the ladder in life.

I took a practice GRE with Magoosh on a whim with no prep today and got a 159-162 average Verbal and 152-155 Math (math score is probably lower than it should be because I was interrupted by a call during my conference period, lost about 5-6 minutes and didn't finish by 2 questions.)

So my guesstimated score should be between 311 and 317?

Does anyone know how accurate this score is?

Also how many points can the average person generally improve on the GRE with prep?

From a Google search my score is roughly in the 60th percentile so I obviously need to improve significantly if I want to get into any solid grad program.

TIA! 🙏

Hi everyone, I just took Power Prep 1 and got the following scores:

• Quant: 7/12 and 15/15
• Verbal: 10/12 and 7/15

Does anyone know the GRE score equivalent of these Power Prep scores? Also, how similar is Power Prep 1 to the actual GRE?

MSCS applicant here. I wrote the gre in early October and reported scores to some colleges. However, due to some issues with my name and passport which I only got to know now, I had to resend the scores to those and a few other target colleges, with 7-10 days left for the deadlines. I have submitted the score report PDF on the supplementary documents. I'm very worried, can someone please help me out or at least give me some reassurance (not false) that the scores, even if reaching a few days late, can be verified with my reported scores?

What is the best book for Verbal? Some said official ETS VR is the best, some said it is too easy compared to the actual GRE. Please suggest as I am really confused about it. What books should I practice from, if any additional is needed?

I have subscribed to Gregmat+ plus. I am currently planning on following his two months plan. Is there any strategy you'd like to share for watching his stuff? For both Quant & VR.

Also, I have 5 LB for Quant, should I follow Manhattan Prep "GRE All the Quant" or "GRE Math Strategies" afterwards, if I want more advanced Quant problems and strategies?

These may have been discussed before but I'd really love your responses.

P.S: For Vocab I'm using Magoosh GRE Flashcards.

Hey everyone,
I just need to rant about the GRE. I’ve taken it twice (only the Quant section mattered for me). The first time, I scored 165; the second, 167—but I barely had enough time to finish both sections. How on earth does the ability to solve math questions in under two minutes relate to any skill required for a PhD? It’s absurd. In mathematics, it’s never about speed; it’s about concepts and deep understanding. For context, I’m applying for a quantitative PhD and have been using advanced math for some time. This test is just so stupid. All students could use this time to learn something useful and not go back to the high school material. What a waste of time it is.

As for the Verbal section, the fact that they made Gregmat delete his videos says a lot. I bet it’s because he was TOO helpful for students. Of course, they claim it’s due to copyright.

Also, I’m from Europe, and the idea of paying extra to ETS for them to send your scores to institutions is ridiculous. Two years ago, I took the CAE and scored at the C2 level. That test actually assesses whether you know English—grammar, structures, and so on. By comparison, the TOEFL is a joke. Anyone can prepare for it in less than a week using basic templates from the internet. The same applies to the GRE’s AWA section. What does it really test? The ability to watch a yt video and memorize a format?

With the CAE, you can use your certificate as you please. With the TOEFL, you pay a ridiculous $290, and then you have to pay again every time you apply somewhere! What exactly are we paying for? Twenty questions on a standardized test? It’s such a scam.

Honestly, I hope universities that rely on ETS exams for admissions realize they’re missing out on talent. In fact, I think they already do.

Ok, that’s it. Hate ETS forever. Universities should be smarter and stop requiring these tests.

I just thought that 3 SD equals 30, so 1 SD might be 10.

https://preview.redd.it/gh3jl1mcqs4e1.png?width=2428&format=png&auto=webp&s=9447c0482cd7f6ff0c9db777a48c2239171ab2ae

Dear all,

Tomorrow is my 4th GRE attempt. Little nervous tbh.

It has been a long ride, I am hoping for the best. Remember me in your prayers!
Good luck to you all.

Cheers!

Hey there I am going to start GRE from scratch plus will also study for TOEFL, will be giving test next year , anyone interested ?,

I appeared for the free Manhattan prep mock test for GRE aa the preliminary test, scored 309. I need mock test resources. I have enrolled for gregmat+.

1. Is there any Discount code for the Powerprep plus tests which is active now? (Dec 2024)
2. Which 3rd party mock tests would you suggest me to buy?

Well I went full on grind mode today— light day at work meant I did a fuck ton of arithmetic problems. I swear to god my girlfriend thinks I have a sudden screw loose with the amount of time I spent hunched over problems during my lunch break and after work.

Took a mock exam today, got a 318 (162 V, 156 Q) with PP2. That quant score stings like a bitch. Honestly should have gotten a slightly higher score, got a few easy verbal questions wrong and even made some slight mistakes in math due to time. Likely a test stamina issue too: the first verbal and math section were pretty good— the latter two sections were more mistake riddled. On the plus side the arithmetic concepts seem to have held up in the test. I’m really focusing on getting foundations down. Prime factoring, sum of multiples, etc is my jam lol.

Mad nervous though because people are saying the math is harder now. I guess though because it’s a scaled score, if it’s harder then that shouldn’t really affect the score received (as in, everyone else will find it harder)? Just trying to reassure myself that I can get my math score up lol.

Tomorrow we begin algebra with gregmat, but one thing I’m def going to do too is retake the arithmetic quizzes and take the quant mountain seriously to keep the concepts fresh. Otherwise they’ll likely slip away.

I have given the GRE twice using gregmat primarily to study.

The first time there was a question asking to calculate the volume of a pyramid (gregmat said this wouldn't be covered).

Today, I think I triggered the hard section for section 2 for quant, and there was a question asking about the "harmonic mean".

Has anyone else seen this? Other topics which we wouldn't expect to be on the GRE? I'm trying to get 168+, so I don't want to get questions which I wouldn't expect to be on it.

Edit: *covered It's been a long day

I did my GRE at home yesterday and I guess I'll share how it went for anyone who is taking it in the future. Overall, it was ok.

Scoring: My written essay score isn't in yet, but I got 159 on verbal and 149 on quant. Which isn't great, but since I am working and studying full time, I only had a few hours to prepare. So a score like that is to be expected.

Proctor and test procedure: The check-in took a while. It took about 15min to connect to the proctor (I clicked on the link 10min before my appointment). Also, when I was finally connected there was a lot of background noise on the proctor's side, which made understanding her quite difficult. There were a lot of other voices talking. She tried to fix that, but it didn't really work, which made communication difficult. For the room requirements we basically did a whole tour of my apartment. I had to show all corners, what's behind and under every space, behind every door. I also had to show the space beneath my bed and chair, which makes sense I guess but also was a bit hilarious. In addition to showing my laptop charger extensively, I also had to put the trashcan that's underneath my desk across the room, together with my phone, after the check-in. Otherwise, my desk was completely cleared except for the laptop, whiteboard and erasable pen, plus cleaning rag. I was also allowed to leave my desktop tower beneath my desk after showing that it was not connected to the laptop I was taking the test on, a screen, keyboard, or anything. Additionally, I had to sit so that the entrance door to my apartment was visible to the webcam at all times, which is mentioned by ETS, so no news there. The test itself went well, a bit easier on verbal than expected, but time management slipped on my end for the second half of quant. As mentioned, that is more a me-issue than a general one.

Good to know: So, there were a few things that were not mentioned prominently by ETS that are good to know for taking the test.

1. One surprise on test day was that the link to connect to the check-in needed to be opened via Google Chrome as the browser. Thankfully I clicked on the link well before my official starting time, so I had time to install Chrome. Maybe it also works with other browsers, but it didn't work with firefox. After check-in, the test itself was in the ETS safe browser.
2. Also, this might be a minor detail, but when using a whiteboard a one-time erasing tool like a paper towel is not allowed. It has to be a cloth towel or something like that. Thankfully, I had a normal cleaning rag lying around that did the job. But I don't think that I've seen that stipulation on the official guidelines, so I'm adding that here.

Imagine a world where every student on Earth collectively decides to boycott standardized exams like the GMAT and GRE, forcing universities to find more meaningful and holistic ways to evaluate applicants. Picture a scenario with zero test-takers and zero applicants to every school. It would be fascinating to witness the reaction of ETS, GMAC, and admissions committees as they scramble to adapt to this unprecedented shift.

Took my first test two weeks ago and got a 160 Q and 157 V.

My studying so far has been learning the Vocab Mountain for GREGmat , and doing an assortment of math problems from Magoosh/Gregmat.

Based on my data given from my test I missed mostly reading comprehension questions on Verbal and an assortment of math questions (ran out of time on the last section)

My thoughts were to get Prepswift and learn RC strategies and then learn the Quant Mountain for Quant

Is this the ideal way to go about doing this, or is there a better way to learn this material?

Hello everyone, I have my GRE on 6 December and I'm so scared but also excited to get it done with, lol. I have been scoring 155-160 in both quants and verbal with the lowest score of 314 and highest score of 325 yet (in various mocks).

I do need to get a 328+ for a good chance at the university that I want to go to; I'll try my best and leave the rest. 💪🏼

What's that ONE advise or tip that you'd want to give me for the exam day ± 2 days?

https://preview.redd.it/16wgnfitzo4e1.png?width=2231&format=png&auto=webp&s=f1bf0c1370be9ad2f4315cf9ba00ce63af8bd474

The correct answer is 2, but I do not understand the logic of it. Can someone please help?

I'm legit writing this in tears. I just scored a 9+9 in QA, both hard sections, in my latest mock from gregmat. My test is in 2 weeks.

For section one I legit could've scored 11 if I had some more time to think. I strategise like this: MCQ, QC, MS, Direct entry and finally I do the graphs question since those eat up my time the most.

For the second section, 3 were mistakes from questions I solved in less than 2 mins, 1 question I didn't even read. And 1 I wholly got incorrect.

Basically if I had the time I could've scored 11+14.

I try to follow the techniques Greg teaches, choosing numbers, comparisons, solving from the choices but they seldom come in handy etc.

Possible time wastes come from:

1. having to draw geometry by hand in 5-10 secs because my brain can't function by staring at the figure on the screen.
2. having to read the questions multiple times to register all the numbers.
3. kraveness towards my own calculations, double checking. Running simple calculations on the calculator.

WHAT DO I DOOO???

Hi everyone! I took the GRE and am currently worried that my score will get cancelled. My room was a bit dark since the only light was not too bright and the blinds where almost completely closed. If the proctor was fine with the lighting and did not say anything, is it possible that they change decision and will cancel my score due to thinking that I may have cheated or am I overthinking it?

The proctor did ask me to close the curtains additional to the blinds but as it got too dark she told me to have the curtains open and it was fine. After the room tour I did the test and at the end she simply told me I could close the window since the test was finished and thanked me.

TLDR: am I fucked or no?

Thx for answer since I am quite stressed atm

Edit: first post was removed because I did not rule 5 Sorry about that! Heres the revised version.

So I just gave my first exam last week and wanted to post my learnings for people who are like me (newbies at GRE and standardized tests in general). Unfortunately I discovered this sub too late and ruined my 1.5 months with ineffective study. I was also too late to fully utilize gregmat but I am going to start from there now. Some of the points below will be obvious to some of y'all, I am just noting them for the absolute newbies like me a month ago.

1. Please, PLEASE don't trust the official guide for QUANT. This has by far been my biggest mistake, and I wish I could tell past me to not fall into the trap (also seriously shame on ETS, if you are charging 40 bucks per book atleast make them representative of the test and cover the entire syllabus. Seriously disgusting behavior, not even going to lie.). So I knew from the getgo my quant skills really needed polishing so I focused on quant more. I decided to go over the math review in the GRE official guide and attempted all of the questions. The math review does not cover all topics, I REPEAT THE MATH REVIEW DOES NOT COVER ALL TOPICS. It completely threw me off when I attempted mocks and 5 lb questions and discovered the amount of things missing from the math review. Arithmetic is the most pathetic section in the math review, it does not detail how to address most types of questions but almost all sections are sub par (except maybe data interpretation which is sufficiently detailed for the questions that do come). Points missing from the review are things such as finding common factors of two numbers, finding the numbers of factors in one number, counting multiples of a number in a set, arithmetic and geometric sequences, finding the averages/sums of the sequences, different types of rates and work questions, harmonic means in finding average speed of a round trip, and a lot more (I can detail more if anyone wants). So please use any tutoring service that goes over all the foundational quant topics in depth so you don't get blind sided by the actual questions.
2. GRE is not about if you know Quant or Verbal reasoning. The GRE is a war of attrition concerning your mental capacity and time. So as soon as you can cover all the fundamental topics via a tutor, don't do questions by topic. If the tutoring service has mixed sets, do that in a timed manner. Forget practicing your conceptual knowledge alone. I completed the Manhattan 5 LB quant section entirely, and yes it did help me learn new concepts and polish my skills, but it gave me a false sense of security. I even timed my self solving one question (tried to solve one question in one to two minutes, harder questions in three) but this IS NOT ENOUGH. Remember the test is a war of attrition, so you have a set time limit for 12-15 questions. You need to get the ability to leave questions you know you can't solve. You need to build stamina and mental capacity to solve questions for 2 hours straight. If you are not a math wizard and are short on time, you have to accept that you aren't getting a perfect score so you can atleast get the next best score. Most importantly you need to practice not burning out! So as soon as you are done with your fundamental course, take mock tests repeatedly.
3. Related to point 2, make mixed sets of your own if you are not using a tutoring service AND INCLUDE AN ESSAY. I am not arguing if the essay is important or not in the application process but one thing is for sure: your mental capacity is 100% going to be depleted after the essay on test day. You need to build the mental stamina to keep going. If you attempt and practice essays separately or leave out essays in your mixed sets, the mixed set will not be representative of the test day because you won't be as tired. So practice mixed sets like 30 questions for both Q and V, and one essay prompt.
4. LOL if you think vocab is enough for TC's and SE's. I thought this, and I was under the false assumption that this was the case in my practice and mock tests. I consistently got 165+ in my mocks for verbal because I had memorized all of the free verbal mountains from the gregmat resource page (the awesome one with the pictures, it really helped!). Did not matter at all. Firstly, I guess it could be luck because the hard words that came, I had never come across them. Secondly, again related to point 2 and 3, as the test progressed I kept getting burnt out and had literally 'duuuuhhhh' moments where my brain was blanking out by the end of it. My last section was verbal and that was an absolute slaughter. Not even the fact that most TC's were 3 blanks, it was that the sentences were so absurd (more on that in the end). The RCs were abhorred too especially given my tank was running empty.
5. The test is way harder than atleast ETS practice materials. This may be subjective or, read under the light of the previous points, may be because I was mentally drained but the test questions were wayyyy harder than I expected especially given the time. The second sections of both Verbal and Quant were just absolute nightmares. Abstrusely written questions, more % of time consuming questions versus simple, long ass RC's where the main point meandered so much you'd think it was an equivocal rambling of a rather loquaciously vivacious sophist, who could not help but inundate her benighted victims with outmoded forms of speech. So yea, include harder questions in your mixed sets OR I was just unlucky. I even got relatively good scores in GRE PP1 (Only three wrong questions in quant, and 4 wrong in Verbal) and PP2 (165Q/160V [yea verbal didn't go great because I had an emergency at my house but it was still easier compared to the real exam]).

So those were the five main points I wanted to detail for the newbies. I wish you all luck and please get a tutoring service ASAP!

Hey everyone, I hope this finds you well. I am just bummed out because I gave my GRE last week and got these results in. I was expecting and planning for Q160 and V165+ (though I got to know apparently Q160 is a trash score but I seriously have no motivation to strike a Q170 because of how absurd I think this test is IMO). I would really like some help on how to do further prep to improve my score. After reading this sub and the testimonials (and the price for third worlders lol) I am going to signup for gregmat, what plan should I use and what would be the best things to focus on within the plans? Thats basically the Tldr of the post but I'll detail some more info and background below:

Weakness:

After preparing for around 1.5 months, giving the mock tests, and finally the actual test, my main weakness is time management. For quant, I can solve most of the questions given ample time, but you barely have enough time to sit and solve properly, so I got way too flustered. Also for some reason I guess I started burning out in the actual test too because some questions were absurdly but after I got home and solved them they were pretty easy to solve. For verbal, I seriously don't know what happened... I was scoring 165+ in mocks but the actual exam was just a slaughter. None of the hard 1000 words I memorized came, the hard words that did come I did not know the meaning of, and the second section was filled with 3 blank TC's and such abhorrently written RC's that I kept blanking out while reading them, and so lost too much time which is why I guess I scored so low in the actual paper vs mocks (159 vs 165+ in mocks).

Background:

I was really stupid coming into the GRE. I basically thought this test would be like the SAT or GED where you could take any of the prep books and get good scores with enough practice and having a good grasp on fundamental concepts and vocab. I also cheaped out a bit (lol) because the GRE is so expensive where I live so I just used the GRE official guide and the 5 lb book for prep (I am going to make another post on what a scam the official guide is and my mistakes so others don't do them). I discovered this sub and consequently Gregmat too late to make use of any of the plans, and thought it'd be a waste of money/time so I just went with most of the free resources online/the books I bought.

My Plan Going Forward:

I am planning to use Gregmat going forward, as I said because of the testimonials on here and its priced very fairly for me. I don't think I need to go over all the fundamental quant lessons because I did do most of the 5 lb and have most of the formulas memorized. I just need strategies and help with tackling difficult questions and managing my time effectively. For verbal, I'll check out the videos but I have no solid steps on improving except taking less and less time each question.

Hi everyone,

I keep on getting the following message when I try creating an account. I have tried contacting support, but they haven't been able to help. Is anyone else unable to log in? Is it just me or is there a site issue?

This site can’t be reached

Check if there is a typo in authnsvc.ets.org.

DNS_PROBE_FINISHED_NXDOMAINThis site can’t be reached

Check if there is a typo in authnsvc.ets.org.

It's 99% all tricks and twists and finding exceptions to the rule. It's got nothing to do with academic math or math used in the classroom. It's toy math. I hate it with every fiber of my being. When you get something wrong, you don't think "Oh, I should learn that next time" because there will be no next time. There's just going to be more tricks and twists that you don't see coming and have no way of predicting. FTS.

Day 2 of GRE studying. Got through another couple days of week 1 Greg videos as I revise exponent, real number and absolute value concepts.

I also spent some time doing verbal practice questions. Easy/medium questions came easy for TC and SE, I get a good amount of hard questions too. But there’s room to improve. Will likely come with practice + more vocab imbibing.

Did some RC practice too just to start flexing those muscles— very light work. Key takeaways so far are a) if it isn’t explicitly mentioned in the passage, it likely isn’t evidence and b) if there are two answer choices that seem extremely similar, it likely isn’t either of them. For example for one of the RC passages I did, I was asked what word most closely meant the highlighted word “discipline”. I was stuck between “field” and “study”, and picked field. It wasn’t either one of those.

Tomorrow is likely going to be quant revision + group 1 and group 2 flash card revising, maybe an arithmetic foundations quiz. And climbing the vocab mountain too. Going to take a mock test day after tomorrow per the Gregmat plan and see how I do. Going to preemptively predict around 320 given what I’ve gotten before. Need a 330+ as an ORM for top MBA programs— quant is seriously the struggle here.

I’ve gotten a bunch of people reaching out from my last post asking to study together. Since my strength is in verbal and my weakness in math, currently only seeking partners who have a 165+ quant score and who will likewise benefit from me helping with verbal. Nothing personal, just want to optimize my time efficiently.

Until tomorrow, plainbread11

I'm planning to take my gre exam at the end of January and looking for a serious study partner. If anyone interested please let me know. I'm starting my prep from day after tomorrow. Dedicated one month is a must .

Edit : Done

Been preparing for GRE on and off for over 2 years while struggling with mental health issues. So much I've learned and yet not getting more than 80% questions right or timing out every time Last two attempts got a quant of 154 and 158 :-/ I've decided to do a GRE journal of whatever I've learnt, especially quantitative, because there's an incredulous amount of things to know in Quant. This won't be coherent and you can look at it as small contribution to the community if you're patient to go through all of it. Feel free to correct in case any of the below is wrong. Planning to do more dumps in future.

1. did you know product of GCD and LCM of 2 numbers is nothing but the product of those 2 numbers?
2. did you know standard deviation of standardized values of any list is 1?
3. also mean of standardized values of any list is 0?
4. did you know numbers of ways of arranging people in a circle is (n-1)! ?
5. did you know if every person shakes hands with every other person in a room, the number of handshakes is n(n-1)/2?
6. did you know mean of a list that's symmetrically (evenly spaced included) distributed is equal to its median?
7. did you know S.D of a list doesn't change if the same # is added or subtracted to/from all numbers in that list?
8. did you know S.D of a list is increased/decreased by a factor of x if x multiplies or divides all numbers in that list?
9. total = A + B - (A and B) + neither A nor B
10. total = A + B + C - (A and B) - (B and C) - (C and A) - 2 (A and B and C) + none of A,B,C
11. total = A + B + C - (A and B only) - (B and C only) - (C and A only) + (A and B and C) + none of A,B,C
12. at least two of three = (A and B only) + (B and C only) + (C and A only) - 2 (A and B and C)
13. Not A or Not B is not same as neither A nor B
14. Not A or Not B = Total - (A and B)
15. instead of going for nPr formula, you can go for choice method or fundamental counting principle. 5P3 is nothing but 5 * 4 * 3 instead of 5!/(2!3!)
16. imagine quadrilaterals as parallelograms (opposite sides equal and parallel) and trapezoids (one pair of opposite sides parallel)
17. all rectangles (all angles 90) and rhombuses (all sides equal) are parallelograms
18. squares are a combination of rectangles and rhombuses
19. if u draw two squares A and B on two legs of a right triangle, the square C on the hypotenuse would have an area equal to sum of areas of A and B
20. when it comes to algebra, divide by zero being undefined is the most rudimentary thing. For instance, x^2 - x = 0. Classic mistake is to do x^2 = x, divide by x on both sides. hence x = 1. But you cannot divide by X on both sides unless you know X cannot be 0. So take out the common term x -> x(x - 1) = 0. Thus, either x or x - 1 should be 0 -> x = 0 or x = 1
21. numbers are of many kinds starting from the smallest set: natural numbers (1,2,3,4,5....), whole numbers(0,1,2,3,4,5,...), integers (.......-4,-3,-2,-1,0,1,2,3,4.......), real numbers (includes decimals in addition to integers), complex numbers (has a real and imaginary part - GRE doesn't care about this)
22. So when the questions says numbers, try numbers like 1/2 and -1/2 also
23. When the question says integers, please do not disregard negative integers.
24. Do not forget a number has negative factors too.
25. irrational numbers are a part of real numbers that are decimals that cannot be expressed as a ratio. for example, square root of 2 or pi (approximately 22/7 or 3.14) cannot be written as a fraction. these are non-terminating non-recurring decimals.
26. irrational numbers are of two types - algebraic and transcendental. Algebraic irrational numbers are a result of an algebraic equation or can be plotted on a graph (Eg; square root of 2) whereas transcendental irrational numbers cannot be plotted on a graph or cannot be a result of an algebraic equation.(Eg: pi)
27. At least two angles of a triangle are acute. Eg: (30, 60, 90) , (60,60,60), (120,30,30)
28. The triangle inequality is based on the fact that shortest distance between two points is a line. That's why sum of two sides of a triangle is greater than other side. -> A+B > C, A+C >B, B+C > A
29. This also applies to quadrilaterals. sum of 3 sides is greater than the 4th side. A+B+C > D, B+C+D > A etc.,
30. GRE doesn't test it - but it's good to know

Sin X = Opposite/Hypotenuse.

Cos X = Adjacent/Hypotenuse.

Tan X = Sin X/Cos X = Opposite/Adjacent

Cosec X = 1/Sin X = Hypotenuse/Opposite.

Sec X = 1/Cos X = Hypotenuse/Adjacent

Cot X = 1/Tan X = Adjacent/Opposite

28. Sum of consecutive integers from 1 to n = n(n+1)/2

29. Sum of first n odd integers = n^2

30. Sum of first n even integers = n (n+1)

31. 2 is the only even prime number

32. Even/Even can be either even or odd Eg: 6/2 = 3; 8/2 = 4

odd + odd = even

even +Even = even

odd + even = odd

even * even = even

odd * even = even

odd * odd = odd

32. if two cars/ppl/trains are approaching each other, they are helping each other get as close as possible. So add their speeds and make one of them static. Imagine two ppl mutually wanting to marry each other.

if two cars/ppl/trains are going in opposite directions away from each other, they are helping each other get as far as possible. So add their speeds and make one of them static. Imagine two ppl mutually wanting to divorce each other.

if a car/train/person is trying to catch up to another person, the one who is ahead doesn't help to get close and typically has a speed less than the person behind and started earlier. So subtract the speed of person ahead from that of person behind and make the slower person static. Imagine a non-consenting marriage where one person is chasing the other.

33. Money earned from Simple interest is same as that of compound interest (compounding annually) when principal, rate of interest are same after EXACTLY ONE YEAR.

34. Without replacement means CONDITOINAL PROBABILITY

35. Binomial distribution formula nCr * P(r) * P(n-r)

n is number of trials

r is number of times a specific outcome occurs

P(r) is probability of success that a certain outcome occurs

P(n-r) is probability of failure that a certain outcome occurs -> likelihood of outcome not occurring

36. to find minimum of a quadratic (parabola - all quadratics are equations of parabolas)

you can differentiate the quadratic and assign it to 0. solve the resultant linear equation for X. plugin that X value back into quadratic to get the minimum.

Or do Completing The Square Method -> Divide the x term's coefficient by 2 and square it. Add and subtract the resultant from the LHS of equation. You could form a equation of form (X-a)^2 + b= 0

when x = a, the quadratic would have its least value -> b

37. standard deviation of a set is always greater than zero whereas standard deviation of a list can be zero when all elements are duplicates of each other

38. a dataset is different from set. a dataset can have duplicates whereas a set cannot.

39. if a bell curve is skewed to the right (longer right tail), mean > median > mode

if a bell curve is skewed to the left (longer left tail), mean < median < mode

if its a normally distributed curve, mean = median = mode

40. most things in the world follow a normal distribution with the average number having most ppl, low number and high number having few ppl

Eg: distribution of wealth. most ppl are middle class with average amount of money, few people are poor and few people are rich.