Skip to Main Content
This is a free sample lesson. Sign up for Magoosh to get access to over 200 video lessons.

Intro to Probability

The essence of probability in the GRE context is explored, emphasizing its definition as a ratio, the significance of randomness, and basic strategies for solving probability problems.
  • Probability is fundamentally a ratio or fraction, representing the number of successes over the total number of outcomes, and must fall between 0 and 1.
  • A probability of 0 signifies impossibility, while a probability of 1 indicates certainty, with most real-world probabilities lying somewhere in between.
  • The concept of randomness in probability is twofold: each individual event is unpredictable, yet the overall pattern of events is predictable.
  • Simple probability problems can sometimes be solved by listing all possible outcomes, though this method is not always feasible for more complex questions.
  • Future discussions will introduce more abstract and general rules for solving probability problems, beyond the basic strategy of listing.
Understanding Probability
The Nature of Randomness