Question 1156162
30 per hour is 2.5 in every five minutes 
probability of 0 when parameter is 2.5=0.0821 
for more than 3 do 0,1,2,3, and that is 0.7576. But want more than 3, so that is 1-0.7576=0.2424

In a 15 minute interval the parameter is now 7.5. Do cdf for 5 and then subtract that from 1.
It is 0.7586 probability. Can check to see if tha makes sense. Cars are coming every 2.5 minutes on average, so expect 6 cars at least in 15 minutes, so that more than 5 would be quite likely.

In a half hour, expect 15 so 10 should be significantly less than half. The probably is 0.0486

Less tha 3 cars arrive in a 10 minute interval. This is 0,1,2
cdf for 2, with parameter 1/6 of 30 or 5.
That probability is 0.1247. Can check that with poisson pdf for parameter 5 and numbers 0,1,2 and get same result by adding the three,