Listing vs Counting vs Probability Rules
Summary
The essence of tackling GRE probability questions lies in discerning which problem-solving technique to employ, be it listing, counting, or formal algebraic probability rules.
- Identify the use of formal algebraic rules by the presence of algebraic expressions or the use of specific terms like 'mutually exclusive' or 'independent'.
- Listing is most effective for problems with very short lists of fewer than ten possibilities, but it's rarely a complete solution technique on its own.
- Counting techniques are suited for problems involving selections from a set with restrictions, indicating a focus on the selection process rather than algebraic computation.
- Considering the complement of the desired outcome can simplify the calculation process, showcasing the need for creativity in problem-solving.
- Developing the right approach to probability problems is a pattern-matching process that improves with practice and careful study of solution sets.
Chapters
00:00
Choosing the Right Tool
01:03
When to Use Algebraic Rules
02:31
The Role of Listing in Problem Solving
03:57
Counting Techniques for Selection Problems
05:18
The Importance of Practice and Pattern Recognition
