In order to access the outer part of a terminal at an airport, you must walk quite some distance in a tunnel that travels under part of the airport. To make the walk less difficult, there is a moving walkway that travels at 2 feet per second. Suppose that Hana can travel 108 feet while walking on the walkway in the same amount of time it takes her to travel 48 feet while walking on the pavement without the aid of the moving sidewalk. How fast does Hana walk?