Probability Conditional Probability for any two events the

Probability - Conditional Probability for any two events

the equation for that is P(E1|E2) = P(E1 and E2) / P(E2)

my question is how do I know which goes first (E1) and which goes second(E2)?

can anyone give me the example?

Solution

It depends on which is in the Denominator.

For your question, E2 is in the Denominator.

Be cafeful to calculate the Conditional Probability for any two events, because the numerator is always the two events happen together. (i.e. P(A and B) )