Combinations with Restrictions

Combinations with Restrictions

In our previous post, we discussed how GMAT combinatorics problems can involve subtracting out restrictions. However, we discussed only PERMUTATIONS and not COMBINATIONS. Today, we’ll take a look at how the same technique can be applied to COMBINATION problems. This...
What Happens When Permutations Have Repeat Elements?

What Happens When Permutations Have Repeat Elements?

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,...
A Continuation of Permutation Math

A Continuation of Permutation Math

Review of Example From Last Post Last time, when we started our discussion of GMAT Combinatorics, we gave a brief example of GMAT permutations in which we had five paintings and asked how many arrangements could be made on a wall with those paintings. As it turns out,...
The Basics of GMAT Combinatorics

The Basics of GMAT Combinatorics

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 scoring on the test and therefore it is best if you are well...