Ответ:
1. Calculate the volume of the wooden beam: 20 cm * 20 cm * 150 cm = 60000 cm³.
2. Calculate the volume of one parquet plate: 1 cm * 5 cm * 30 cm = 150 cm³.
3. Calculate the number of plates: 60000 cm³ / 150 cm³ = 400 plates.
2. Calculate the volume of one parquet plate: 1 cm * 5 cm * 30 cm = 150 cm³.
3. Calculate the number of plates: 60000 cm³ / 150 cm³ = 400 plates.
