In Duolingo speaking and writing sample are marks calculated?

Yes, ofcourse. 

Duolingo English Test Score is scored on a scale of 10 to 160. The Duolingo exam pattern and marks are bisected into the overall score and four subscores, as follows:

Literacy 10 to 160

Conversation 10 to 160

Comprehension 10 to 160

Production 10 to 160