As a current full-time student in Columbia Business School’s executive MBA program and a full-time online marketing maverick for Knewton, I often get asked this question: Are you completely nuts? How can you balance the demands of school and a career without sacrificing one for the other?
We’re happy to introduce the Knewton Weekly Math Challenge. Every Wednesday we’ll post a very difficult quant question. The first person to answer correctly in the comment field below will win the new Knewton T-shirt. After the right answer appears in the comments (you can only post one answer, and you must explain how you arrived at your answer — so take your time), we’ll post a full explanation. Here’s the first question. Good luck!
In a certain game, a player begins with a bag containing tiles numbered 1 through 10, each of which has an equal probability of being selected. The player draws one tile. If the tile is even, the player stops. If not, the player draws another tile without replacing the first. If this second tile is even, the player stops. If not, the player draws a third tile—without replacing either of the first two tiles—and then stops. What is the probability that at the conclusion of the game, the sum of the tiles that the player has drawn is odd?
Tone is the feeling or emotion associated with a passage or a part of a passage. An author creates tone with the specific words he or she chooses to include. Adjectives and adverbs give authors a chance to express emotion because they are explicitly descriptive; much of an author’s tone is created in the way he or she describes things.
Sometimes an entire passage has a tone. Take this example:
Don’t worry, this is not nearly as complicated as it sounds. Knewton instructor Cole Entress lays it all out for you in this short lesson.
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Prime Factorization: My single favorite topic on the GMAT. Hands down.
My passionate (some would say evangelical!) advocacy of prime factorization results not only from my finding prime numbers so intrinsically fascinating in and of themselves, but also from the plain and simple truth that prime factorization proves surprisingly useful on questions on which prime numbers aren’t even mentioned.
An idiom is an expression that on a literal level may not make perfect sense, either grammatically or logically, but has become so thoroughly accepted that the misuse of this expression is a grammatical error.
The correct form of an idiom is determined by conventional usage rather than by rules of grammar. Therefore, the best way to deal with unfamiliar idioms is to memorize their correct form. The following list of common idioms is not exhaustive, but it is a good starting point.
Here is a list of common idioms:
A lot of students write in asking questions about the personal statement. And for good reason: It’s your one shot to really introduce your personality to an admissions board. It’s like you’re running for President and you’re at the convention. You get a podium and only a few minutes to present your case to the voters.
With that in mind, here are some time-worn Do’s and Don’ts of personal statement writing.
Don’t: Talk about the school too much. Admissions officers already know how great their institutions are (or aren’t). Customization is important, but two or three sentences about the school should suffice.
This is the last installment of an FAQ series on Computer-Adaptive Tests (CAT). Check out part 1 and part 2 as well.
You can be in the 99th percentile overall even if you didn’t score in the 99th percentile on either of the sections, because the overall score is calculated separately from the section scores and their percentiles. So, for example, you could get a 48 on Quantitative (86th percentile), a 45 on Verbal (98th percentile), and a 760 overall (99th percentile).
In any GMAT course, one of the very first things taught about the Data Sufficiency section is that the two statements are true and do not contradict one another. It’s a point that’s easy to gloss over and completely overlook during the hustle and bustle of your test prep.
But this supposedly self-evident point gets many students into trouble when dealing with YES/NO questions, because they mistakenly try to prove or disprove the statements rather than the prompt.
This is a follow to my last piece, CAT FAQ: Beginner.
Most exams are linear assessments, like the SAT or your 10th grade history final. These are scored by counting the number of questions you answer correctly, and sometimes by penalizing for each question you answer incorrectly. The result, a raw score, is then converted to a scaled score, like the 600-2400 range for the SAT.
A computer-adaptive test (CAT) works very differently. It doesn’t really care as much about how many you get right or wrong, but rather which questions you get right and wrong. The CAT algorithm estimates your ability based on a variety of criteria, including the difficulty of a question. After each question, it evaluates your response and updates this estimate. When the test is over, the algorithm converts your quantitative and verbal ability estimates into the quantitative and verbal scaled scores, and then separately combines your quantitative and verbal ability estimates to calculate the overall score.
Success at Reading Comprehension depends on two limiting factors: (1) The rate at which the information you’re reading enters your brain and (2) what your brain is able to do with it. The latter, being able to act on information, is a composite skill that is acquired through years of learning.
Fortunately for test-takers, the first factor — your speed of reading — can be seriously increased with a few simple adjustments in technique. You can learn how to read faster as long as you’re willing to put in the practice. Here’s how to do it.
I’ve received a number of inquiries from the community about the GMAT algorithm, so I thought it best to reply in article form.
An algorithm, generally, is a usually efficient set of well-defined steps the following of which results in the solution to some pre-defined problem. In the case of a CAT algorithm, the problem is to reliably and efficiently estimate a student’s ability in a reasonable amount of time. Some CAT algorithms seek to solve this problem by selecting one question at a time, each subsequent question selected based on all of the student’s prior responses. Other algorithms look only at the most recently-answered question. Still others evaluate responses to specific groups of questions. CAT algorithms also vary with regard to the explicit criteria they use to select the next question (or sets of questions) to administer. Some try to minimize total measurement error. Others try to maximize the precision and accuracy of measurement for each question administered. Still others try to select questions that will most refine the current ability estimate. As a consequence, CAT algorithms can vary greatly from one another, depending on the specific implementation of the algorithm, and the intent of the algorithm developers.
Many answer choices on the GMAT are written to be tempting. Some answers will be blatantly wrong, but most will only be slightly wrong.
That’s why you have to pay close attention to passage wording in Reading Comp and Critical Reasoning. Both sections make you read huge chunks of text closely but quickly, so when you’re scanning the questions for a passage the words start to run together. Here are some tips for keeping things straight.
Forget how to find the volume of a cylinder? Curious how to find the surface area? Like cool Powerpoint art? If yes to any of the above, check out this video.
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During your entire educational career, teachers have probably told you the same, shopworn motto: Deep understanding is more important than memorizing facts. You always knew that this was silly—those teachers would invariably test you on facts, and if you didn’t know them, then a “deep understanding” of them was impossible. That’s as true on the GMAT Quantitative section as it was in high school history.
