Let’s be real: GRE probability questions can feel like a black hole of confusion. One minute you’re confident, the next you’re second-guessing every step.
But here’s the good news: With the right mindset and strategy, you can turn probability from a pain point into a power move on test day. In this guide, we’ll simplify key concepts, walk through examples, and point you to killer resources to level up your game.
🧠 What Is Probability, Anyway?
Probability is the measure of how likely an event is to occur. It’s always a number between 0 and 1:
- 0 = Impossible
- 1 = Certain
For example, the probability of flipping a fair coin and getting heads is 0.5.
On the GRE, you’ll face word problems that test your understanding of this concept under various scenarios. And while some questions can be tricky, every single one is beatable with a clear understanding of the basics.
🧮 Start with the Core Formula
At the heart of most GRE probability questions is this formula:
P(A) = Favorable Outcomes / Total Possible Outcomes
Let’s say you have a bag with 3 red marbles and 7 blue marbles. The probability of pulling a red marble is:
P(Red) = 3 / (3 + 7) = 0.3
📄 Bookmark This: ETS Math Conventions PDF
🔗 Independent vs. Dependent Events
Understanding how events interact is a must for the GRE. There are two key types:
- Independent Events: One event doesn’t affect the other. (e.g., Flipping a coin and rolling a die)
- Dependent Events: One event does affect the other. (e.g., Drawing two cards from a deck without replacement)
Tip: If it says “without replacement,” think dependent.
🎥 Watch this Khan Academy explainer for a quick visual breakdown.
🧩 Use Visual Aids (They Work!)
When GRE problems get complex—think multiple conditions or sequences—draw it out. Seriously.
- Tree diagrams help with sequential events.
- Venn diagrams are great for overlapping groups.
These tools make the problem less abstract—and way easier to solve.
📚 Check out this Manhattan Prep post for smart strategies and visuals.
🧪 Practice Like It’s Game Day
You can read about probability all day, but nothing beats practicing real GRE-style questions.
Here’s where to go:
- 🧠 Khan Academy – Probability Practice
- 📝 Magoosh’s GRE Math Practice
- 🎯 ETS Official Practice Questions
🧱 Build a Strong Math Foundation
Probability sits on top of core math concepts:
- Fractions
- Ratios
- Percents
- Combinations & permutations
If you’re shaky in any of these, take a step back and brush up. It’ll make solving probability questions 10x easier.
✅ Refresher: GRE Math Review from ETS
📌 TL;DR: Your GRE Probability Game Plan
- Master the basic formula
- Know the difference between independent & dependent events
- Draw it out—use visuals like tree diagrams
- Practice daily with high-quality GRE questions
- Brush up on foundational math skills
Probability doesn’t have to be your GRE nemesis. With a clear plan and consistent practice, you’ll go from guessing to crushing. 💪
Got a question or stuck on a specific type of problem? Drop it in the comments or shoot us a message.