Answer:
20 m/s westward
Explanation:
Taking eastward as positive direction, we have:
 is the velocity of Bill with respect to Amy (which is stationary)
 is the velocity of Bill with respect to Amy (which is stationary)
 is the velocity of Carlos with respect to Amy
 is the velocity of Carlos with respect to Amy
Bill is moving 5 m/s eastward compared to Amy at rest, so the velocity of Bill's reference frame is

Therefore, Carlos velocity in Bill's reference frame will be

and the direction will be westward (negative sign).
 
        
             
        
        
        
Answer:
Humus
Explanation:
Its Humus I believe. I remember learning something like this. 
 
        
             
        
        
        
Answer:
huh,? can you explain the question more please