How Long is a...
How Long is a Chinese name.
The humor in this statement is that it can be read in two different ways: "The name 'How Long' is Chinese.", or "How many letters does a Chinese name have?".
That makes this a pun. The only reason why this pun works is that How Long sounds like it could actually be a Chinese name.
I'm not going to call this racist, because it doesn't actually make fun of Chinese people.