Question

In an urn are 13 balls, which are numbered from 1 to 13. It is randomly taken a ball.

We define the following events:

A: An even number will be drawn.
B: A number divisible by 3 is drawn.
C: a number divisible by 4 is drawn.
Give the following probabilities.

P (A) =
  (| B A) = P
  P (A | C) =

P (B) =
  P (B | A) =
  P (B | C) =

P (C) =
  P (C | A) =
  (| B C) = P

Answer 1

Conditional probability P(A/B) is the probability of event A when event B is already happened .