Response B is better because it explains the math clearly and stays honest about the missing quantity column. Response A reaches the same answer, but it sounds more certain than the image supports. B feels accurate, careful, and useful.

Response B provides superior value by offering clear mathematical explanations while maintaining transparency about the incomplete quantity column. Although Response A arrives at the same conclusion, it presents information with greater certainty than what the image actually demonstrates. Response B comes across as precise, cautious, and genuinely helpful to users.