Independent Events

[Alchemist4lyf]

Salam. I wanted to ask, is there any other way or equation to show independence? Like, there's one where p(a and b) = p(a) x p(b). But is there any other one. And for dependent events as well. Is there any other equation?

 

[abcde]

Wasalam! =)
Another equation is P(A or B) = P(A) + P(B).

 

[Alchemist4lyf]

Thanks abcde. But i knew that one too. I was thinking more along the lines of something that would allow me to prove independence or dependence. Can you help with that?

 

[abcde]

These are the major ones tested in your O'level Maths syllabus. When do you have to prove independence/dependence?

 

[Alchemist4lyf]

As in, for example, i got two events, A and B, and their probabilities. And i got P( A or B). Now they say, is this mutually exclusive or not? I know how to do that, as P(a) + p(b) should equal 1. But how will i know, if the events are independent, or dependent?

 

[abcde]

The formula P(A and B)= P(A) x P(B) is normally used for independent events because when events are mutually exclusive (cannot occur at the same time), P(A and B) = 0. So the 'AND' rule is only applicable for independent events.

 

[SalmanPakRocks]

Yes abcde is right!
Independent events are like this
P(A intersection B) = P(A) x P(B)