GMAT Prep Roller Coaster

[moneyman]

A certain roller coaster has three 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 probabilitiy that the passenger will ride each of the 3 cars??

0
1/9
2/9
1/3
1

[samirpandeyit62]

3!/3^3

=6/27 =2/9 C

[moneyman]

Hey Samir dont mind but can you please explain how you arrived at the answer because I am not that good at probability questions..

[samirpandeyit62]

let the cars be represented by A,B,C

so total possibilities = 3*3*3 (each time he can select one of the 3 cars)

& for him to select each of the cars A,B,C, he can do this using all permutations of ABC i.e 3!

so reqd P =3!/3^3 =2/9

Sorry Moneyman for not providing the expln, actually I'm trying to practise solving Q's on the scratch paper. 8)