Compare the motion of two sailboats. Which sailboat was moving at a higher speed?

 - a sailboat that moved 75kilometers in 5hours
 - a sailboat that moved 90kilometers in 5hours
Look at the distance each sailboat moved and the time it took to move that distance.
One sailboat moved 90 kilometers in 5 hours.
The other sailboat moved 75 kilometers in 5 hours.
Notice that each sailboat spent the same amount of time moving. The sailboat that moved 90 kilometers moved a farther distance in that time. So, that sailboat must have moved at a higher speed.