您好吗？

How are you doing?

How are you?

How're you doing?

Source: Tatoeba

Sentence Composition

1 您好 nínhǎo hello (polite)
=2 吗 má (coll.) what?
=2 吗 mǎ used in 吗啡 mǎfēi
=2 吗 ma (question particle for "yes-no" questions)