If you move 100 meters in 65 seconds , what is your speed?

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)

1.5 m/s

the answer is b