Compare the motion of two mountain bikers. Which mountain biker was moving at a lower speed?

 - a mountain biker who moved 175kilometers in 5hours
 - a mountain biker who moved 85kilometers in 5hours
Look at the distance each mountain biker moved and the time it took to move that distance.
One mountain biker moved 85 kilometers in 5 hours.
The other mountain biker moved 175 kilometers in 5 hours.
Notice that each mountain biker spent the same amount of time moving. The mountain biker who moved 85 kilometers moved a shorter distance in that time. So, that mountain biker must have moved at a lower speed.