A lecturer commutes daily from his home to UMP. The average time taken for a one-trip is 30 minutes, with a standard deviation of 4 minutes. Assume the distribution of time taken of the trips is normally distributed. If the lecturer leaves hishome at 7.55 am and all the students will be left the lecture hall after they wait from 8.00 am until 8.10 am, what is the probability that he enter the class without students?