数学求助- GWD15 29

ENJ0Y

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 coller coaster. If a certain passenger is to ride the roller coaster 3 times, what is probability that the passenger will ride in each of the 3 cars?

Answer: 2/9
求解过程，谢谢！

koei2009

正规排列组合的说法我也忘了怎么说- -
不过你可以这样想：要满足3次坐不同的车，第一次做哪个都一样，概率是1.第二次要坐剩下两个，概率是2/3.最后一次么，显然是1/3. 乘起来。

ENJ0Y

谢谢！ 我原来把第一次选择用1/3 来乘了。