Question: Traveling in opposite directions, buses A and B are passing each other at the relative speed of 25 km/h, while a passenger on bus A walks toward the back of the bus at the speed of 5 km/h. What is the velocity of the passenger on bus A relative to bus B?

  Options: 
 A. 20 km/h in the direction of bus A
 B. 20 km/h in the direction of bus B
 C. 30 km/h in the direction of bus A
 D. 30 km/h in the direction of bus B
Answer: A