Calculate what fraction of gas molecules
(a) traverses without collisions the distances exceeding the mean free path `lamda` ,
(b) has the free path values lying within the inerval from `lamda` to `2 lamda`.

Explanation

(a) The fraction of gas molecules which traverses distances exceeding the mean free path without collision is just the probability to traverse the distance `s = lamda` without collision.
Thus `P = e^-1 = (1)/( e) = 0.37`
This probability is
`P = e^-1 - e^-2 = 0.23`.