Gotham City subway trains are always late for weekday morning commuters. In fact, the moring trains are, on average 8 mins late with a standard dev of 2 mins. Suppose the morning subway trains are randomly and indep. selected.
A. What is the probability that the sum of their minutes late is less than 10 minutes?
B. What is the probability that the second train selected is at least 2 mins later than the first subway train selected?