Question 1

What is the probability formula?

Accepted Answer

Basic probability is P(event) = favorable outcomes / total outcomes. For two events the union is P(A or B) = P(A) + P(B) − P(A and B), and conditional probability is P(A|B) = P(A and B) / P(B).

Question 2

How do I calculate lottery probability?

Accepted Answer

Use the combinatorial mode: set total items n to the pool size, successes k to how many you pick, and desired to how many you want to match. The probability is C(k,desired) × C(n−k, k−desired) / C(n, k), all computed instantly in your browser.

Question 3

What is the difference between independent and dependent events?

Accepted Answer

Independent events do not affect each other, so P(A and B) = P(A) × P(B). Dependent events do affect each other, and you must use the conditional probability P(A and B) = P(A) × P(B|A).

Question 4

Can probability be greater than 1?

Accepted Answer

No. A valid probability is always between 0 (impossible) and 1 (certain), or 0% to 100%. If your inputs produce a value outside this range, check that the intersection is not larger than the individual event probabilities.