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Part $1$

Two students have started a business to seal driveways during the summer months. They rent a pickup truck and a power sprayer. With this they will use a tar based spray to seal asphalt driveways. Past experience has shown that the best time to sign up customers is to ring their doorbells between$5$:$00$ and$8$:$00$ p$.$m$.$ on any weekday evening. Any jobs that they obtain will be completed the next day. In the months of$$ June, July and August they find that they get an average $2$ customers per hour ringing doorbells.

What is the probability that they will get from $5$ to $9$ jobs in an evening of$$ soliciting?