This is a potentially tricky topic. First, consider these practice questions. 1. Which value(s) of x satisfies the equation above? I. –1 II. 4 III. 9 I III I & II I & III I, II, & III 2. What is the value of y? A full discussion of these problems will come at the [...]
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Three Algebra Formulas Essential for the GMAT
First, a few practice problems. 1) The numbers a, b, and c are all positive. If , then what is the value of ? Statement #1: a – b = 3 Statement #2: = 7 2) Given that (P + 2Q) is a positive number, what is the value of (P + 2Q)? Statement #1: [...]
GMAT Math: How to Divide by a Square Root
A lot of students, especially those away from math for a long time, get lost when trying to divide by a square root. First, consider these three practice questions. 1. In the equation above, x = 2. Triangle ABC is an equilateral triangle with an altitude of 6. What is its area? 3. In the [...]
GMAT Math: Can you divide by a variable?
Question #1: In the equation, can you divide both sides by x? Question #2: In the equation (x – 3)(x + 5) = (2x + 1)(x + 5), can you divide both sides by (x + 5)? Question #3: Question #4: Dividing by a variable or by an algebraic expression The short answer is: [...]
GMAT Plugging In Strategy: Always Start with Answer Choice C
Learn this powerful math trick for GMAT Problem Solving questions. First, try these two practice GMAT Quantitative section Problem Solving questions. 1) Bert left the house with N dollars. He spent 1/4 of this at the hardware store, then $7 at the dry cleaners, and then half of what was left at the grocery store. [...]
Algebra on the GMAT: How to Factor
Master this fundamental algebraic skill which you will need on test day! First, try these practice problems. 1) (x – 4)(x + 6) (x + 4)(x – 6) (x – 4)(x – 6) (x – 2)(x + 12) (x + 2)(x – 12) 3) If , then |a| + |b| + |c| + |d| = [...]
FOIL on the GMAT: Simplifying and Expanding
First, try this question: 1) If you find this problem relatively easy, probably most of this post will be for you as well. If this problem makes your head spin, you have found exactly the post you need. Monomials and Binomials First, a review of terms. In algebra, any product of numbers and variables [...]
GMAT Solution and Mixing Problems
Attention, mad scientists out there! Consider these two practice questions. 1) A scientist has 400 units of a 6% phosphoric acid solution, and an unlimited supply of 12% phosphoric acid solution. How many units of the latter must she add to the former to produce a 10% phosphoric acid solution? 200 400 500 600 [...]
Simplifying Radical Expressions on the GMAT
Practice questions Let’s start out with a couple practice questions. 2) What is the length of the diagonal of a square with area 48? The geometry of those questions is not too difficult, but the trick is how to handle those radicals. If that befuddles you, this is just the post for you. Distributing [...]
Scale Factors on the GMAT: Percent Increases and Decreases
First, try these practice questions: 1) Every length in a 45°-45°-90° triangle increases by 20%. By what percent does the area of the triangle increase? 20% 25% 40% 44% 80% 2) At a certain pizza parlor, the diameter of a large pizza is 40% larger than the diameter of a small pizza. What is [...]
