Probability Calculator — 公式
## How to Calculate Probability
### Formula
**P(A) = Favorable outcomes / Total outcomes**
Probability measures how likely an event is to occur, ranging from 0 (impossible) to 1 (certain). Multiply by 100 to express as a percentage. The odds in favor are the ratio of favorable to unfavorable outcomes.
### Formula
**P(A) = Favorable outcomes / Total outcomes**
Probability measures how likely an event is to occur, ranging from 0 (impossible) to 1 (certain). Multiply by 100 to express as a percentage. The odds in favor are the ratio of favorable to unfavorable outcomes.
计算示例
A bag has 3 red balls out of 10 total. What is the probability of drawing a red ball?
- Favorable outcomes = 3 (red balls)
- Total outcomes = 10 (all balls)
- P(red) = 3 / 10 = 0.3
- As a percentage: 0.3 * 100 = 30%
- Odds in favor: 3 / (10 - 3) = 3/7 ≈ 0.4286