For women at Hartford College, times to run 400 meters are normally distributed with a mean of 84 seconds and a standard deviation of 6 seconds. What percentage of the times are more than 72 seconds?

Randy and trey take turns cleaning offices on the weekends. it takes randy at most 4 hours to clean the offices. it takes trey at most 6 hours to clean the offices. what is the greatest amount of time it would take them to clean the offices together? 2.4 hours 2.5 hours