# Algebra Concepts in GMAT Quant

Permutations and Combinations: Overview for GMAT Quant

**Important note: The formulas below are only appropriate for problems involving selection from a single source with no repetition.** Before we get into the details of permutations vs combinations, here's a metaphor: Situation 1: You walk into a restaurant and order a "pepperoni and sausage pizza", only to receive a "sausage and pepperoni pizza". Should you be upset?...

Three tips for solving inequality questions in GMAT Quant

While most equations indicate a clear relationship between two statements, inequality problems ask test takers to answer questions based on limited information....

Solving percentage change problems in GMAT Quant

Solving questions on percentage changes in GMAT Quant can consume too much time if you don't know how to tackle them. Here are some time-saving tips. Consider the following question from the 2016 Official Guide: Last year the price per share of Stock X increased by k percent and the earnings per share of Stock X increased by m percent, where k is greater than m....

Using patterns to solve exponent questions in GMAT Quant

Large exponents on the GMAT can be intimidating if you aren't prepared. Keep these tips in mind when solving them: Say the question is: What is the units digit of 2329? It seems as if a calculator would make life much easier here, but we don’t actually need one. The solution Let’s not worry about the number 23, but let’s focus on the units digit of 23, which is 3....

Solving problems with perfect squares in GMAT Quant

An important area of GMAT math is the concept of a perfect square. First, we should define it. A perfect square is an integer that is the square of an integer. Let’s look at an example of a question involving perfect squares from GMAT Tutor’s bank of practice questions: x and y are integers....

Simplifying exponents in GMAT Quant

Consider the following example: 28 x 46 x 320 In the GMAT it is important to identify the difference between the base and the exponent. The bases in the above example are the 2, 3 and 4. The exponents are the 6, 8 and 20. A basic rule is to make the bases the same or make the exponents the same....

Absolute values in GMAT Quant

Remember the first time you saw an absolute value like |x| on a GMAT question, probably many years removed from your most recent algebra class? If you had a difficult time remembering what to do with it, don’t worry. A quick refresher will have you back on track in no time. I find that the easiest way to think about absolute value is spatially, in terms of distance and location....

Combinatorics: a useful method for solving them

Some of the trickiest questions on the GMAT are those that ask you to consider three options, which are then combined in various ways in the answer choices. Consider the following question from the GMAT Tutor question bank: If x is a positive integer greater than 2, the product of x consecutive positive integers must be divisible by which of the following? ...

Percentage change

There are many questions on the GMAT involving percentage change. As with many areas of GMAT math, one formula will make your life much easier when solving such questions. Consider the following question from GMAT Tutor’s question bank: The price of a gallon of gasoline was $30 on the 15th of March....

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