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Intro to Probability


Mike McGarry
Lesson by Mike McGarry
Magoosh Expert

Summary
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.
Chapters
00:00
Understanding Probability
03:33
The Nature of Randomness