معنی That’s absurd اینجا چی میشه؟

A: Maximum 50 kilometers per hour.
B: You mean a pedestrian is not allowed to go faster than 50 kilometers an hour?
A: Ha, ha, ha.
B: What’s so funny? Why are you laughing?
A: That’s absurd. It means vehicles mustn’t exceed that speed not pedestrians, ha, ha, ha.