In: Math
Lisa is at a bus stop. The times between successive bus arrivals are independent and identically distributed exponential random variables with mean 3 minutes. While lisa is waiting, Mindy calls to say she will arrive in exactly 3 minutes. Lisa will wait for Mindy and they will ride a bus together. Calculate the probability that Lisa will miss the first and both Lisa and Mindy will catch the second bus.
3minute is the Time interval is taken, and average number of bus arrival in the given time period is 1, so the event (bus arrives) follows Poisson (1).