whats the probability

Question

A bag contains 12 red checkers and 6 black checkers. You will randomly select two checkers, one at a time, without replacement.

a.)In how many ways can you select two checkers so that at least one of the checkers is red? List the ways.
b.)What is the probability that you select a black checker and then a red checker? Show your work.

Answer 1

hi Kristina,

 

a) you could choose :

 

red, black

 

black, red

 

red, red

 

b) p(black, red) = (6/18)(12/17) = 72/306 = 4/17

 

have a good night