user: Question: What is the Length/Fuel of the bus with a Quantity of 30?
Columns: ['Length/Fuel', 'Model', 'Year Built', 'Quantity', 'Floor Styling', 'Wheelchair access']
Types: ['text', 'text', 'text', 'real', 'text', 'text']
Sample row: ['40ft./Diesel Bus', 'Neoplan AN440', '2000-2003', 206.0, 'High', 'Yes']
SQL:

assistant: SELECT "Length/Fuel" FROM "Table" WHERE "Quantity" = 30.0;