The speed is equal to the distance travelled divided by the time taken:

All we do is use the number for distance, and the number for time from the question.
Distance = 100 meters
Time = 65 seconds.
Now lets divide the Distance by the Time, to get the speed:


The units of the speed will be: meters / seconds, or m/s for short, because we divide the distance (in meters) by the time (in seconds)
Answer:
1.5 m/s