Really need help on 1 physics question,10 points best answer!?

This is not a big explanation, but the observer is in a frame, that does not move relative to the train and neither does the observer, so he is moving at 0mph. the train is moving with 50 mph and so is the man in the train as he throws the ball forward it accelerates to 10 mph inside the train which is 60 mph for the observer from outside. because the speeds add. maybe i have got something wrong, but i dont believe so.