Probability

1 out of 6 Nummy Cereal boxes has a bobblehead of Ricky Gervais inside. If Katie buys 3 Nummy Cereal boxes, what is the probability that at least one will have a Ricky Gervais bobblehead inside? Express your answer as a common fraction.     

(1 / 6) • 3  =  3 / 6  =  1 / 2    

_.