For every 10 min. the number of people getting attended follows a Poisson distribution with an expected value of 2. the balcony only works from 9am till 12 am, and only attends 40 people at Max.

now the question is: what is the probability of not attending all clients in one morning (9am till 12am)?

ps: ok so from wat i got is the expected value of180 min (9am till 12am) is 36 ...