Calculating Speed v = d/t

Question 1

If a kitten below walks 10m in 5s, how fast is it moving?

Answer 1

v = d/t
v = 10/5
v = 2 ms-1

Question 2

Two cats walked for 30m. They begin walking after 10s have passed, and stop moving after 25s have passed, calculate how long does it take them to move and their speed.

Answer 2

final - initial 
25 - 10
15 seconds to move
30m/15s
= 2ms-1

Question 3

A shark starts moving 13m from the aquarium glass and moves until it is 36m from the glass. How many meters did it move?

Answer 3

23meters