The answer will be 'yes' if the provided sentence contains an explicit mention that answers the given question. Otherwise, the answer should be 'no'. Instances where the answer is implied from the sentence using "instinct" or "common sense" (as opposed to being written explicitly in the sentence) should be labeled as 'no'.

Let me give you an example: Sentence: Jack played basketball for an hour after school, after which he was very tired. 
Question: How long did Jack play basketball?
The answer to this example can be: Yes.
Here is why: The answer to this question (an hour)  lies in its text.

OK. solve this:
Sentence: However , by the time Schahzenan's army reaches the city , Scheherazade's plan has worked . 
Question: When did Scheherazade's plan work?
Answer:
Yes.