Compare the motion of three motorboats. Which motorboat was moving at the highest speed?

 - a motorboat that moved 180kilometers east in 5hours
 - a motorboat that moved 360kilometers south in 5hours
 - a motorboat that moved 90kilometers east in 5hours
Look at the distance each motorboat moved and the time it took to move that distance. The direction each motorboat moved does not affect its speed.
Notice that each motorboat moved for 5 hours. The motorboat that moved 360 kilometers moved the farthest distance in that time. So, that motorboat must have moved at the highest speed.