GMAT Math Articles

  • One More RTD Table Problem: Average Rates – Part 1

    One More RTD Table Problem: Average Rates – Part 1

    by on January 28th, 2015

    My last several posts have been devoted to the use of a table to answer rate problems. Today’s post will assume familiarity with that table, so please take a look back at these posts is you’re not already familiar … Read More

  • Calculating Perfect Squares on the GMAT

    Calculating Perfect Squares on the GMAT

    by on January 26th, 2015

    The GMAT is an exam that evaluates how you think. The test is designed to measure your reasoning skills and gauge how successful you will be in business school. This means that the test is not simply trying to ascertain … Read More

  • Using the RTD Table for a Complicated Problem

    Using the RTD Table for a Complicated Problem

    by on January 25th, 2015

    My last few blog posts have involved rate problems about simultaneous movement. In each of these problems we discovered exactly two travelers who either (1) moved at their own constant rates for the entire time period … Read More

  • REVIEW: Manhattan GMAT’s 6th Edition GEOMETRY Strategy Guide

    REVIEW: Manhattan GMAT’s 6th Edition GEOMETRY Strategy Guide

    by on January 23rd, 2015

    As I specified in my review of Algebra Strategy Guide, Manhattan GMAT’s 6th Edition Strategy Guides arrived on 2nd December. If you just came to know about these guides, I encourage you to first go through the … Read More

  • A Different Use of the RTD Table: Part 2

    A Different Use of the RTD Table: Part 2

    by on January 22nd, 2015

    Let’s recap where we left off yesterday. We were working with this diagram: We wanted to solve for Mary’s time, t. In every row the relationship among rate, time, and distance is the same: RT=D. In this diagram the … Read More

  • A Different Use of the RTD Table: Part 1

    A Different Use of the RTD Table: Part 1

    by on January 21st, 2015

    In my last couple of posts (Using Diagrams to Solve GMAT Rate Problems Part 1 and Part 2) I used a Rate-Time-Distance table, (or RTD table) to solve the most common sort of rate problem: a combined-rate problem in which … Read More

  • Tackling Max/Min Statistics on the GMAT – Part 3

    Tackling Max/Min Statistics on the GMAT – Part 3

    by on January 19th, 2015

    Welcome to our third and final installment dedicated to those pesky maximize/minimize quant problems. If you haven’t yet reviewed the earlier installments, start with part 1 and work your way back up to this post. … Read More

  • Tackling Max/Min Statistics on the GMAT – Part 2

    Tackling Max/Min Statistics on the GMAT – Part 2

    by on January 18th, 2015

    Last time, we discussed two GMATPrep® problems that simultaneously tested statistics and the concept of maximizing or minimizing a value. The GMAT could ask you to maximize or minimize just about anything, so the latter … Read More

  • Using Diagrams to Solve GMAT Rate Problems: Part 2

    Using Diagrams to Solve GMAT Rate Problems: Part 2

    by on January 17th, 2015

    In Part 1 we used what is called an RTD table to solve a fairly typical rate problem. Today I want to revisit the problem in Part 1 to make a simple point: There’s more than one correct way to use the table. If you … Read More

  • Tackling Max/Min Statistics on the GMAT – Part 1

    Tackling Max/Min Statistics on the GMAT – Part 1

    by on January 10th, 2015

    Blast from the past! I first discussed the problems in this series way back in 2009. I’m reviving the series now because too many people just aren’t comfortable handling the weird maximize/minimize problem variations … Read More

  • Using Diagrams to Solve GMAT Rate Problems: Part 1

    Using Diagrams to Solve GMAT Rate Problems: Part 1

    by on January 9th, 2015

    Diagrams are great! Like all types of scratch-work, diagrams can forestall cognitive fatigue because working a problem out on paper is much less demanding than doing all the work in your head. Diagrams can also help you … Read More

  • The 2 Most Common Errors in GMAT Data Sufficiency

    The 2 Most Common Errors in GMAT Data Sufficiency

    by on January 8th, 2015

    GMAT Data Sufficiency questions test your ability to analyze a quantitative problem and recognize which information is necessary to figure out the solution.  What a data sufficiency question does NOT test you on is your … Read More

  • GMAT Practice Problems: Similar Geometric Figures

    GMAT Practice Problems: Similar Geometric Figures

    by on January 5th, 2015

    Here are four practice problems involving similar figures. 1) In the figure, KLMN is a square, and angle KJN = 45°. Find the area of figure JKLMN. 2) In the diagram, HJLM is a square, and GH = 10. Find the area of … Read More

  • Variables in the Answer Choices, Part II: Pitfalls with the Input-Output Approach

    Variables in the Answer Choices, Part II: Pitfalls with the Input-Output Approach

    by on January 4th, 2015

    In the last article, we learned the algebraic approach and the input-output approach for solving questions with variables in the answer choices (VIACs). In that article, I ended by saying that, while the input-output … Read More