Answer to Question #199874 in Statistics and Probability for Abby Pham

Question

A jar contains 8 red marbles, numbered 1 to 8, and 12 blue marbles numbered 1 to 12.

a) A marble is chosen at random. If you're told the marble is blue, what is the probability that it has the number 6 on it?

   

b) The first marble is replaced, and another marble is chosen at random. If you're told the marble has the number 1 on it, what is the probability the marble is blue?

Answer 1

a)

$$P(6|Blue)=\dfrac{1}{12}$$

b)

$$P(Blue|1)=\dfrac{1}{2}$$