Probability of getting a seat in the train car

1.1k Views Asked by At

A train has got five train cars, each one with N seats. There are 150 passengers who randomly choose one of the cars. What is the probability that everyone will get a seat?

I think that what is asking me is "what is the probability that each wagon is chosen by no more than N passengers"?

Given a wagon, the probability of having $n<N$ people in it is given by $$p_N=\sum\limits_{n=0}^N \binom{150}{n}0.2^n 0.8^{150-n}$$.

I thought of the answer being $p_N^5$.. but I think that the events

  • wagon a is chosen by no more than N passengers
  • wagon b is chosen by no more than N passengers
  • wagon c is chosen by no more than N passengers
  • wagon d is chosen by no more than N passengers
  • wagon e is chosen by no more than N passengers

are far from being independent... So what could I do? Thanks a lot