
probability problem
The arrival of trucks on a receiving dock is a Poisson process with a mean arrival rate of two per hour.
(a) Find the probability that exactly 6 trucks arrive in a twohour period.
(b) Find the probability that the time between two successive arrivals will be more than 3 hours.
Please help me in solving the above problem!!!!
Thanks!!

Poisson Probabilities are a matter of plugging into the formula.
$\displaystyle \lambda\;=\;2\;per\;hour$
n = 6/2 hours = 3 per hour
Calculate it. Let's see what you get.
For the second, Poisson Wait Times are Exponential. Let's see what you get.

I have a nearly identical question to this, for part (b) since the interarrival times are exponentially distributed would it be:
$\displaystyle \lambda = 2(3) = 6$ for your rate, then you would have:
$\displaystyle \int_3^\infty \lambda e^{\lambda t} dt = \int_3^\infty 6 e^{6 t} dt$ ?