Given the rationale, provide a reasonable question and answer. Step-by-step reasoning process: The boys cannot be working on their bicycles and skateboards at the same time.
 The question and answer:
Test for natural language inference.
Premise: "A couple of boys are in a gym with partially assembled bicycles."
Hypothesis: "The boys are working on their skateboards."
Is the hypothesis entailed by the premise?
Options:
- yes
- no
- it is not possible to tell
The answer is no