If the probability of observing a car (read: at least one car) in 20 minutes on a highway is 609/625, what is the probability of observing a car (read: at least one) in 5 minutes (assuming constant default probability)?

(In reply to

re(3): Auto-suggestion by Charlie)

Great answer, Charlie, thanks.

*Edited on ***April 9, 2004, 3:31 pm**