How many homeless people could Bill Gates fed with his wealth?

If he bought everyone in America a $5 burger it would cost him about $2 billion. So he could feed everyone a burger a day for about two months before he spent it all. 

Or he could hire a 2 million member personal army for a year at $50,000 and overthrow the corrupt state governments of poor states. 

Or he could do like George Soros and give organizations money to push political agendas and stir up trouble and political upheaval. 

I would Hope None they need to get a Job and feed themselves

None even if he tried.  On any day, the poorest person any place in America has at  least three times as times as much food as a human can eat.  First, they get food at the stores by using their SNAP card.  Then they can go by the local Food Bank and eat again.  Two meals not enough?  Lets go check out the Salvation Army for a third meal.  They are not hungry.  They are fat and will die young.

He is doing better than that.  He is giving away much of his money to educational charities, so people in hot sunny countries can learn the difference between 'fed' and 'feed'.

None Not His problem

None. He has no stockpile of food. To buy food he would need to sell stocks, possessions, and real estate TO YOU AND ME and the general public, so it would be our money he is using to feed the homeless. [He could HOUSE some homeless people in buildings he owns.] <He would use his income to heat those buildings and keep the plumbing working.

Why would he do that? He already helps people with the largest charitable foundation in the world. I don't suppose you knew that. Bill & Melinda Gates Foundation works to help all people lead healthy, productive lives. In developing countries, it focuses on improving people's health and giving them the chance to lift themselves out of hunger and extreme poverty.