Note: Sorry if this is considered a uni question, I'm not sure, so you'll have to tell me.
A busy switchboard receives 150 calls an hour on average. Assume that the probability, , of getting k calls in a given minute is:
where the average number of calls per minute.
a) Find the probability of getting exactly 3 calls in a given minute.
b) Find th probability of getting at least 2 calls in a given minute.
I'm not sure how to attempt this. I'm sure I'm missing something obvious, but there's no examples in this text to guide me. Any assistance would be great.