The business bureau surveys all the convention visitors who stay at the hotel nearest the convention hall.
To find the complement of an event you have to figure out what the probability is of not choosing a 6
since 1/13 is the probability that 6 is going to be choosen.
the other 12/13 is used for every other card accept for the 6:)
hope this is right
have a good one:)
merry Christmas:)