user: Question: How many Liquidat (c) have a purpose of dual (machine & hand composition)?
Columns: ['Sn/Sb (%)', 'Liquidat (°C)', 'Solidat (°C)', 'Hardness ( Brinell )', 'Purpose']
Types: ['text', 'real', 'real', 'real', 'text']
Sample row: ['6/15', 261.0, 240.0, 23.0, 'Routine']
SQL:

assistant: SELECT COUNT("Liquidat (°C)") FROM "Table" WHERE "Purpose" = 'dual (machine & hand composition)';