Compare the motion of two gray whales. Which gray whale was moving at a higher speed?

 - a gray whale that moved 25miles in 10hours
 - a gray whale that moved 30miles in 10hours
Look at the distance each gray whale moved and the time it took to move that distance.
One gray whale moved 30 miles in 10 hours.
The other gray whale moved 25 miles in 10 hours.
Notice that each gray whale spent the same amount of time moving. The gray whale that moved 30 miles moved a farther distance in that time. So, that gray whale must have moved at a higher speed.