Would the contraction for du and les be des?

Impossible!

du is a contraction of de + le -- singular.

les is plural

http://french.about.com/library/pronunciation/bl-contractions.htm

No, the contraction for "du" and "les" is not "des." The contraction for "du" (from the preposition "de" and the article "le") and "les" is "des." However, "du" is a contraction of "de" and "le," which means "of the" or "some" in English, while "des" is the plural form of "un" or "une," which means "some" in English.

To understand the contraction, it's important to know the basic rules of French contractions.

1. "De + le" contracts to "du":

Ex: Je viens du cinéma. (I come from the cinema.)

2. "De + les" contracts to "des":

Ex: Elle parle des fleurs. (She speaks about the flowers.)

So, in summary, the contraction for "du" and "les" would not be "des." Instead, it would be "des" when contracting "de + les."