GWD math 1-2 哪位解释一下？

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?

本人概率都忘的差不多了，哪位NN能给解释一下？

yup,2/9.how did you get it?

答案是2/9

第一次从三辆车中任选一辆都可以，所以概率是3/3，第二步三辆车只有两辆可选2/3，第三步只有一辆可选1/3，最后相乘得2/9。