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cars on the road

If 609/625 is the probability of seeing a car in the next 20 minutes, then 16/625 is the probability of seeing no cars.  Let's call that probability P20,  and call P5 the probability of seeing no cars in a 5-minute interval.  (We'll assume all 5 minute intervals are alike. )

If cars travel independently then P20 is just P5 raised to the 4th power, and  P20 = (16/625) = (2/5)**4  => P5 = 2/5.

So the probability of seeing a car in a 5-minute interval is 3/5.

Chuck Boyer
Thursday, August 05, 2004

this is not a very clear question.

it has multiple answer depends on how you depict the problem:

see a car  means at least one car or one car only

michael
Tuesday, December 28, 2004

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