Help with physics problem, about motion.?

A spaceship ferrying workers to Moon Base I takes a straight line path from the earth to the moon, a distance of 384,000km. Suppose it accelerates at 20.0m/s2 for the first 15min of the trip, then travels at constant speed until the last 15min, when it accelerates at -20m/s2, just coming to rest as it reaches the... moon. A) what is the maximum speed attained? B) what fraction of the total distance is traveled at constant speed? C) what total time is required for the trip?