One of our wonderful student guest bloggers, Candice Batts, recently wrote about her on-going fight to conquer GMAT word problems. Translating word problems into quantifiable, workable information is her GMAT Achilles’ heel. Candice called me out at the tail end of that post and my response to her is something everyone wrestling with the same GMAT Problem Solving demon should hear.
First of all, the strategies Candice lists in the last paragraph of her post are spot on. Creating and taking quizzes in her online account (who doesn’t love the Quiz Banks tool?!?) and then reviewing BOTH the right AND wrong answers is critical to increasing your problem solving (PS) question skill level. Also, making flashcards for the “Big Two” strategies (Picking Numbers and Backsolving) is a good idea to help train up on what type of PS question set-ups are good candidates for these strategic approaches. Further, … Read full post
Greetings, I would like to announce that I have officially figured out that my biggest challenge on the GMAT is translating word problems into workable equations that allow me to get to the right answer quickly.
When I first started studying for the GMAT, the words from these long and confusing paragraphs would float in one ear and out the other. I would desperately try to hold on to each word, analyzing each one looking for a clue that would help me. Then I would read one question over and over and over like the answer was going to suddenly appear and say ‘I was hear all along!!’ That’s the habit that Kaplan instructors train you NOT to do first. With this strategy, no wonder the words were just swimming around in my head with no meaning!
As I said, my Kaplan instructor showed me how to strategically read … Read full post
For about a year, I always used the same method to solve the following GMAT problem:
How many liters of water must be evaporated from 50 liters of a 3 percent sugar solution to get a 5 percent sugar solution?
“This is simple percentages,” I would say. “Just start by taking 3% of 50 liters, which is 3 over 100 times 50, which comes out to 1.5 liters sugar…”
But one day, teaching this same quantitative problem, a student’s hand shot straight up. “Yes, James?” I said. (That wasn’t his real name, by the way, but it will do.)
“Eli, who cares about the sugar?”
I paused. “Well, the sugar will help us figure out the solution.”
“But you don’t need it!” James explained. “I’ve been a chemical engineer for years, so I do this problem all the time. The sugar is a constant. The amount of sugar doesn’t change, … Read full post
Everyone studying for the GMAT wants to identify the skills that will lead directly to the greatest point increases. While this can be difficult to do, given the adaptive nature of the exam, some skills definitely do come into play more often than others.
One of the most important skills to master for the GMAT is prime factorization. Finding prime factors can be useful on many different types of questions. On test day, if you are stuck on a question and unsure of how to solve, remember the big number rule. The big number rule is simply this: if you see a big number, one that is so large it is unreasonable to work with, find its prime factors. Once you have those factors, you should be able to simplify.
Every positive integer that is not prime, with the exception of 1, can be broken down into a … Read full post
Not surprisingly, most GMAT test takers have a background in the business world. As such, many readers have worked on a committee formed from a larger group of employees. Every time a committee is formed in this fashion, you are, in fact, doing a GMAT problem. More specifically, you are attempting one of the most dreaded question types on the GMAT quantitative section – combinations.
While these questions can be tough, by thinking about the real life experience of forming a committee, you can more easily understand exactly what a combinations question is asking you to do. Let’s say that your business has ten employees and needs to create a committee of four people. If you want to determine how many different possible committees you could create, you would use the combinations formula, n!/[k!(n - k)!], where n is the number of people with which you start (in this case … Read full post
One of the big GMAT skills that is often overlooked by students is translation. Any time you decide approach a word problem using algebra, you will need to translate the English in the question stem into an algebraic equation. While this seems as if it would usually be fairly straightforward, the GMAT will often find ways to make it more difficult. A translation error will often lead to a trap answer, so it is essential that you learn how to translate difficult statements before test day.
To understand why translation can be more difficult than it seems, think about translating a foreign language. If you only need to translate one word, you can usually just find the equivalent word in English. Similarly, if a GMAT problem uses the phrase “more than” you know that it must translate to addition.
However, when you try to translate an entire sentence from … Read full post
Most students learn that absolute value is the positive version of a number. Thus, the absolute value of 7 is 7 and the absolute value of -7 is also 7. While these absolute values are correct, many GMAT problems will be more straightforward if you learn the true definition of absolute value, which is the distance a number is from zero on a number line. Thus, the absolute values of 7 and -7 are 7 because both numbers are 7 away from zero on a number line.
To understand how absolute value works, imagine you live in a house right in the middle of a block. The street has 5 houses to the left of your house and 5 houses to the right of your house. Whether you walk two houses to the left or two houses to the right you will be 2 houses away from your home. Now, … Read full post
The only thing you need to know about sequences is that a sequence is an ordered series of numbers. Really, that’s it. Many sequences are defined by specific mathematical formulae or properties, and most sequences of note continue on infinitely, but neither of those are necessary. All you need to have a sequence is an ordered list.
Of course, that raises the question of why they are tested at all. One might assume that the simplicity of sequences means that they should be trivial and a waste of the testmaker’s time. Conversely, it could seem that since simple definition covers an enormous range of possibilities, it would be impossible to expect students to understand them all. But in fact, sequences test a very specific skill: your ability to decode instructions.
Think about all of the time you need to spend studying for the GMAT. Then imagine that, instead of taking the GMAT by yourself, you were allowed to get a friend to take the test with you. The amount of work you would need to do on test day would certainly shrink, but by how much? This type of question is at the crux of combined work problems.
Your first thought, if you could split the GMAT with a friend, might be that you would only need to do half of the work. But that would not necessarily be the case. The friend that you picked might not be as good at math as you, so in the time you could do two math problems, your friend could only do one. Now, of the 37 questions on the quantitative portion of the GMAT, you will need to plan to … Read full post
Despite the name, irrational numbers aren’t crazy. You might think they are, and you wouldn’t be alone. The followers of Pythagoras (yes, the right triangle guy!) believed that irrational numbers were heretical; supposedly, they threw the first person to prove irrationals existed into the ocean! But in fact, the word ‘irrational’ refers to the mathematical concept of the ‘ratio.’ Irrational numbers are numbers that cannot be expressed at the ratio of two integers, a/b.
There are an infinite number of irrational numbers, though far fewer are of mathematical note. If you’ve ever studied statistics or calculus, you’ve probably run across the natural number e, and ancient architects had a centuries-long love affair with φ, the golden ratio. But on the GMAT, there are only two types of irrational numbers that will be relevant to you: π and radicals.
Both of these irrationals will appear most often in geometry questions, and … Read full post