A certain roller coaster has 3 cars, and a passenger is equally likely to ride in any 1 of the 3 cars each time that passenger rides the roller coaster. If a certain passenger is to ride the roller coaster 3 times, what is the probability that the passenger will ride in each of the 3 cars?
first car = it could be any one of the three
second car = it could be any one of the remaining two
third car = it is the remaining one.
p(first) = 1
p(second) = 2/3
p(third) = 1/3
so p(each of 3 cars) = 1 x 2/3 x 1/3 = 2/9