If rate problems bring to mind moving trains, then there is no more iconic type of probability question than the coin toss. And there is good reason for this—coin tosses represent a fair portion of probability questions on the GRE. Even if a question doesn’t invoke the coin toss, the way we approach a coin toss problem […]

# Archive | GRE Data Analysis

## Do Permutations Make Your Head Spin?

On a recent post I went over factorials. Now let’s try a word problem that actually uses the factorial sign. Five students must sit in 5 chairs. How many different ways can they sit? (A) 30 (B) 60 (C) 4! (D) 5! (E) 6! In this problem we have a set number of people. Our […]

## Probability Workshop — Part I

At the mere mention of probability on the GRE students’ eyes glaze over and all conversation stops, save perhaps for the hushed admission that they don’t like probability. While probability can be very difficult—and many of the publishers give it short shrift (so there are a lack of practice problems)—keeping a few concepts in mind […]