Earl runs 75 meters in 30 seconds
we are asked to find how many meters he runs per second
distance per unit time is also called speed
therefore we need to find the speed of Earl
If Earl runs 75 m in 30 seconds
finding speed means to find the distance he ran in 1 second
so in 30 seconds if he ran 75 m
then in 1 second he runs - 75 m/30 s = 2.5 m/s
speed of Earl is 2.5 m/s