Jason recently ran a marathon. Given that the mean finishing time for all

Jason recently ran a marathon. Given that the mean finishing time for all runners was 258 minutes with a standard deviation of 44 minutes and that finishing times were approximately normally distributed, find
(a) the percent of finishers who ran faster than Jasons time of 3 hr 30 min.
(b) a time that was the 33rd percentile (33% of finishers were under that time)
(c) the percent to runners who finished between 3 hours and 4 hours