To Give or Not to Give?

I was on my way to meet up with Sam for lunch in Chinatown. As I was in the train reading a newspaper, I suddenly heard a voice from a man. I heard him say, "Sorry to bother everyone, but I would like to ask if you could all give me some money to buy something to eat..." During this time , no one said anything and as I looked up slightly, all I could see was one person ready to give some coins to the homeless man and everyone else pretended they didn't hear anything (myself included). He was then slowly walking through the carriage and as he went closer to me I was thinking to myself whether I should give him any money. At the same time I was thinking, 'How did he afford to get on the train?', 'Did he actively try to find work?' etc.. By the time I finished pondering, he had already walked past me and even the girl next to me have given some coins to him. Was I wrong not to give money to him? What if he really needed it? If you were in a similar situation, what would you have done?