Very simple motion problem, i just cant get it

[stangeroo]

When the moving sidewalk at the airport is broken, as it often seems to be, it takes you 50 s to walk from your gate to baggage claim. When it is working and you stand on the moving sidewalk the entire way, without walking, it takes 75 s to travel the same distance.

How long will it take if you walk while riding on the moving sidewalk

 

[Hippo]

Consider the sidewalk your unit of length. Use this to produce the average velocities describing your motion in either situation.

K, now what can you do with those velocities that might describe the new situation?

 

[thepatientmental]

If you walk while riding on the moving sidewalk, it will take you less than 50 seconds to travel from your gate to baggage claim. This is because the moving sidewalk is already helping you move forward, so walking will make you travel even faster. The exact time will depend on your walking speed, but it will definitely be less than 50 seconds.