Set up a system of equations and solve.

A company is introducing a new soft drink and is planning to have $48$ advertisements distributed among TV ads, radio ads, and newspaper ads. If the cost of TV ads is $$500$ each, the cost of radio ads is $$200$ each, and the cost of newspaper ads is $$200$ each, how can the ads be distributed among the three types if the company has $$15,000$ to spend for advertising?

$($Let $x$ denote the number of TV ads, $y$ the number of radio ads, and $z$ the number of newspaper ads. Let $z$ be the parameter.$)$