arrive to a service center randomly and independently at a rate of 10 per hour on average, what is the probability of 5 cars arriving in a given hour?...

If cars arrive to a service center randomly and independently at a rate of 10 per hour on average, what is the probability of 5 cars arriving in a given hour?

a. 0.038

b. 0.1755

c. 0.05

d. 0.0067

If cars arrive to a service center randomly and independently at a rate of 10 per hour on average, what is the probability that exactly 10 cars will arrive during a 30 minutes period?

a. 0.1277

b. 0.1755

c. 0.6160

d. 0.018