We have to show work and I need help quickly please help!

3. The homicide rate in a certain city is 2 homicides per week on average.

a. Find the probability that there will be 3 or more homicides this week. Hint: think about which random variable you can use to model the number of events that happen in a week if you know the average.

b.If a homicide occurs today, find the probability that the next homicide will occur within the next 5 days. Hint: think about which random variable we can use to model time between events.

c.What is the probability that there will be exactly 4 weeks out of the next 5 that will have 3 or more homicides? Hint: think of having 3 or more homicides in a week as a "success".

d. Counting the current week as week number one, what is the probability that the first week to have 3 or more homicides will be the 2nd week? Hint: think again of having 3 or more homicides in a week as a "success".