Aboat traveled 210 miles downstream and back. the trip downstream took 10 hous. the trip back took 70hours. what is the speed of the boat in still water. what is the speed of the current

Michael gose to a theme park and rides two different roller coasters that both begin on a raised platform his height while on the first roller coaster measured in feet from the platform height can be modeled by the following graph where t is the number of seconds since the ride began