Sandra moves 14 m in 2 minutes. what is sandra's average velocity (in m/s)?
a. 1.98 m/s
b. 0.23 m/s
c. 0.78 m/s
d. 2.56 m/s

-- If you want to talk about "velocity", you need to know the direction of the motion.  There's no direction information anywhere in this question, so the best we can do is talk about Sandra's "speed".

-- Speed = (distance covered) / (time to cover the distance)

Sandra's Speed = (14 m) / (2 minutes) = 7 m/minute.

But it wants the answer in m/second.

-- (7 m/min) x (1 min/60 sec) =  7/60 m/s

Speed = 0.117 m/s

The correct answer is not on the list of choices.

Choice-B ... 0.23 m/s ... is what you would get if Sandra covered the 14 meters in ONE minute.  But since it took her 2 minutes, her average speed is only half of that.

The response to this question is "none of the above" or "0.117 m/s".

d) physical means can be used to separate the components of air.