A House Has 3,450 Sq Ft of Floor Space and Is

A house has 3,450 sq ft of floor space and is divided into 3 heating/cooling zones. The first zone, the upstairs, has 1,122 sq ft. The main living area is the second zone covering 1,525 sq ft of space. The third zone is the basement where the recreation room, laundry, half bath, and home shop are located. How much floor space is included in the third zone in square feet?