by Focus Tutoring | Jun 24, 2021 | Combinatorics, GMAT, Quant

By: Apex GMAT Contributor: Svetozara Saykova Date: 24th June 2021 Combinatorics can seem like one of the most difficult types of questions to come across on the GMAT. Luckily there are not many of them within the exam. Still these questions make up the top level of...
by Focus Tutoring | Mar 16, 2021 | Combinatorics, GMAT, Probability, Quant

By: Rich Zwelling, Apex GMAT Instructor Date: 16th March, 2021 Now, we’d like to take a look at an Official GMAT Probability problem to pull everything together. The following is a good example for two reasons: 1. It illustrates a quirky case that is difficult more...
by Focus Tutoring | Mar 2, 2021 | Combinatorics, GMAT, Quant

By: Rich Zwelling, Apex GMAT Instructor Date: 2nd March, 2021 So far, we’ve covered the basics of GMAT combinatorics, the difference between permutations and combinations, some basic permutation and combination math, and permutations with repeat elements. Now, we’ll...
by Focus Tutoring | Feb 25, 2021 | Combinatorics, GMAT, Probability, Quant

As promised in the last post, today we’ll discuss what happens when we have a PERMUTATIONS situation with repeat elements. What does this mean exactly? Well, let’s return to the basic example in our intro post on GMAT combinatorics: If we have five distinct paintings,...
by Focus Tutoring | Feb 23, 2021 | Combinatorics, GMAT, Quant

Last time, we looked at the following GMAT combinatorics practice problem, which gives itself away as a PERMUTATION problem because it’s concerned with “orderings,” and thus we care about the order in which items appear: At a cheese tasting, a chef is to present some...