Solving the problem of the rich individual means you'll get profits quickly as the rich will be willing to pay big for their problem to be solevd. One problem of the rich is security because they alway feel insecure therefore if you start up a personal security agency you can charge them big. The poor individuals mightn't have big money to pay you but you can use the advantage of their numbers therefore if you get millions of poor people to use the service you're offering, you'll get rich.
But there's much of an economic benefits to the state when an individual direct his services to helping the poor. It reduces the financial burden of social welfare on government in catering for those poor and less privileged when private individuals intervenes in giving them help by solving a few of their needs.
To be honest, I genuinely feel happy solving or even helping solve the problem of the poor than rich people. Rich people have their funds, resources and assets to solve any issues and hardships. They could pay for people to fix their problems while poor people mostly rely on the government and people who are able to lend them a hand. Poor people need help but the government only provide a temporary assistance. They deserve a long term help to survive and live life not just a temporary food on the table.
Both need help but rich people are more able to solve their without getting help from anyone.
Sarcastically speaking, the funny thing is that the problem of the poor is not always a big problem to solve , very minimal that with little funds solution will be made available unlike to the rich (big-man big-problem) their problems are not usually money related problems, and that's what makes the solutions to most of their problems difficult to meet.