Answer:
here the ball we land exactly into the hand of the person who throw it upwards.
Step-by-step explanation:
Since train is moving with uniform speed as

now when we throw a ball vertically upwards with certain velocity then due to inertia the ball will automatically start moving in horizontal direction with same speed as that the speed of the train
so while ball is in air then the distance moved by the ball in horizontal direction will be same as that the distance moved by the train in horizontal direction.
So here the ball we land exactly into the hand of the person who throw it upwards.