A jar contains 7 red marbles, numbered 1 to 7, and 11 blue marbles numbered 1 to 11. Find the following probabilities. Round solutions to three decimal places, if necessary.

a) A marble is chosen at random. If you're told the marble is red, what is the probability that it has the number 3 on it?

P

(

P(

3 | red)

=

)=

b) The first marble is replaced, and another marble is chosen at random. If you're told the marble has the number 8 on it, what is the probability the marble is red?

P

(

P(

red | 8)

=

)=