Oh, you asked me that before. You'll find the answer right there at the bottom...

5 seconds sound clip from the Miracle on 34th Street (1947) movie soundboard.

You can hear this line at 00:32:03 in the Blu-ray version of the movie.

Quote context

[...]

- It's a home for old people. That's right.

- I want to talk to the doctor in charge.

- How many days in the week?

- Seven.

- Who was the first president of the United States?

- George Washington.

- How much is three times five?

- Oh, you asked me that before. You'll find the answer right there at the bottom...

- I'm conducting this examination.

- How much is three times five?

- The same as it was before - 15.

- You're rather nervous, aren't you, Mr. Sawyer? Do you get enough sleep?

- My personal habits are of no concern to you.

[...]