The given text contains a mathematical error related to the square root symbol, which is not applicable in this context. There are no other spelling, typographical, grammatical, or OCR errors. The text is properly formatted and presented in a clear, coherent manner. Therefore, no corrections are needed.
Corrected TEXTS:
Find the mass and weight of the air at 20°C in a living room with a 4.0 m x 5.0 m floor and a ceiling 3.0 m high, and the mass and weight of an equal volume