Based on data that was collected over the past several months, the average time between arrivals to the gym on a Monday between the hours of 7am to 7pm is 35min.Work-outs occur at random, and hence the arrival of customers to the gym follows a purely random process.

1. What probability distribution would you use to model the time between customer arrivals?
2. Suppose a customer just arrived, what is the probability the next customer will arrive in less than 20 minutes?