요금제

확률 계산기

원하는 결과의 수와 전체 결과의 수로 확률을 구하거나, 두 독립사건(A 그리고 B, A 또는 B, 둘 다 아님, 정확히 하나)을 결합합니다.

원하는 결과, 예: 빨간 공 3개
일어날 가능성이 같은 모든 결과

결과

값을 입력하고 계산을 누르면 결과가 표시됩니다.

공식

P(E)=favourable outcomestotal outcomesP(E) = \frac{\text{favourable outcomes}}{\text{total outcomes}}

For equally likely outcomes.

P(not E)=1−P(E)P(\text{not } E) = 1 - P(E)

The complement: the event does not happen.

P(A∩B)=P(A) P(B)P(A \cap B) = P(A)\,P(B)

Both happen, when A and B are independent.

P(A∪B)=P(A)+P(B)−P(A∩B)P(A \cup B) = P(A) + P(B) - P(A \cap B)

At least one happens.

이 계산기 사용법

  1. For one event, enter how many outcomes you want and how many there are in total.
  2. For two independent events, enter each probability as a fraction (1/2) or a decimal (0.5).

풀이 예제

3 red balls in a bag of 8

P(red) = 3/8 = 0.375 = 37.5%.

P(not red) = 1 − 3/8 = 5/8.

The odds of red are 3 : 5 (3 for, 5 against).

자주 묻는 질문

What does independent mean?

One event does not change the chance of the other — like two separate coin flips.

What is the difference between probability and odds?

Probability compares favourable outcomes with all outcomes (3/8); odds compare favourable with unfavourable (3 : 5).