The arrival of people in a museum follows a Poisson random variable with an average rate of 6 per hour. The sensor at the entrance makes one mark for each four people who walk in (1 after the fourth person walks in, 2 after the 8 th person walks in, 3 after the 12 th person walks in and so on) and the controller monitoring this sensor has no other information about the number of people who have entered the museum. If the controller sees 0 on the sensor ten minutes after the opening, what is the probability that no one has walked into the museum? opening, what is the probability that no one has walked into the museum?.