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

### Instruction:
Which episodein season 3 had 175020 for a production code?

### Inputs:
table_name: table, columns: ['No.', '#', 'Title', 'Director', 'Writer(s)', 'Original air date', 'Prod. code', 'U.S. viewers (million)']

### Response:
SELECT # FROM table WHERE Prod. code = 175020