figure out the questions

My house has three levels- a basement, the main floor, and an upstairs. The ​basement ​is ​12.5 feet below​ the main floor. The ​upstairs ​level is ​14.5 ft above ​the main floor.

1. What rational number could represent the level of the basement?

2. What rational number could represent the level of the upstairs?

3. What does 0 represent in this situation?