Below is an instruction that describes a task. Write a response that appropriately completes the request.

### Instruction:
What is the Length/Fuel of the bus with a Quantity of 30?

### Inputs:
table_name: table, columns: ['Length/Fuel', 'Model', 'Year Built', 'Quantity', 'Floor Styling', 'Wheelchair access']

### Response:
SELECT Length/Fuel FROM table WHERE Quantity = 30