GMAT Word Problems

Problems range from easy to hard. 1) On a ferry, there are 50 cars and 10 trucks.  The cars have an average mass of 1200 kg and the trucks have an average mass of 3000 kg.  What is the average mass of all 60 vehicles on the ferry? (A) 1200 kg (B) 1500 kg (C) […]

1) A librarian has 4 identical copies of Hamlet, 3 identical copies of Macbeth, 2 identical copies of Romeo and Juliet, and one copy of Midsummer’s Night Dream. In how many distinct arrangements can these ten books be put in order on a shelf? (A) 720 (B) 1,512 (C) 2,520 (D) 6,400 (E) 12,600   […]

If you haven’t been following our series on RTD tables, take a few minutes to catch up: Using Diagrams to Solve Rate Problems: Part 1 Using Diagrams to Solve Rate Problems: Part 2 A Different Use of the RTD Table: Part 1 A Different Use of the RTD Table: Part 2 Using the RTD Table […]

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 with the RTD table: Using Diagrams to Solve Rate Problems: Part 1 Using Diagrams to Solve […]

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 covered by the story, or (2) moved at their own constant rates  and started and stopped simultaneously. If you’d […]

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 bottom row looks the most promising, since it alone contains only the variable for which we’re […]

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 two travelers move in opposite directions simultaneously.  (If you haven’t read those posts and aren’t […]

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 keep in mind a few simple truth about the […]

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 to visualize relationships, and can make problems more concrete. Generally though, we use diagrams to generate equations, which […]

First, a few practice problems.  Remember: no calculator! 1) If $5,000,000 is the initial amount placed in an account that collects 7% annual interest, which of the following compounding rates would produce the largest total amount after two years? (A) compounding annually (B) compounding quarterly (C) compounding monthly (D) compounding daily (E) All four of […]

First, try these challenging GMAT Quantitative problems, all variations on a theme, as you will see. 1) Seven children — A, B, C, D, E, F, and G — are going to sit in seven chairs in a row.  The children C & F have to sit next to each other, and the others can […]

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? (A) 200 (B) 400 […]

Understand this common type of special counting on the GMAT!  Question #1: On Monday, there were 29 bananas in the cafeteria.  No new bananas were brought in after Monday.  Two days later, on Wednesday, there were 14 bananas left.  How many were eaten in that time? Question #2: In January of last year, MicroCorp start-up […]

Learn this powerful method for unlocking devilishly complicated problems about sets.    Practice questions First, try these challenging 700-level practice questions. 1) At Veridux Corporation, there are 250 employees. Of these, 90 are female, and the rest are males.  There are a total of 40 managers, and the rest of the employees are associates.  If […]

Understand how to handle these tricky upper level Quant problems!  Definitions A sequence is a list of numbers that follow some mathematical patterns.  More formally, a sequence is a function whose inputs are limited to the positive integers.  Terms are denoted by a letter for the whole sequence, and in the subscript, the index, which […]