Yuki and the Lake Clean-up Day Poster
Yuki is a second-year student at a public high school in Shiga. On Monday she sees a poster for the Lake Clean-up Day. The poster says: meet at the gym at 8:30; gloves and bags are provided; bring your own water bottle; the clean-up finishes at 11:00; a simple lunch is served only to students who signed up by Wednesday; if it rains, the event moves to Thursday at the same time. Buses leave Shiga Station at 8:00 and 8:20 and take 10 minutes to the gym. Yuki has tennis practice near the station until 8:05, and it takes her 5 minutes to walk to the bus stop. She signed up on Tuesday but forgot her water bottle. She wants to know whether she can still get lunch and which bus to take.
1. Which bus should Yuki take? Show the time calculation and explain why the other bus does not work.
Read the worked answer
Practice ends at 8:05, and the walk to the bus stop takes 5 minutes, so Yuki reaches the stop at 8:10. The 8:00 bus has already left. The 8:20 bus is the only remaining choice; with a 10-minute ride, it puts her at the gym at 8:30, exactly the meeting time. That means she should take the 8:20 bus and go directly to the gym, with no time to spare. The 8:00 bus is impossible because she is still at practice at 8:05, not because the poster forbids it.
2. Can Yuki receive lunch? Explain using the separate conditions on the poster.
Read the worked answer
Yes. The lunch condition is signing up by Wednesday. Yuki signed up on Tuesday, so she meets that condition. The water bottle is a separate instruction for the clean-up itself, not a condition for lunch. She should still deal with the bottle before 8:30 - for example, fill it at school or buy one - but forgetting it does not cancel her lunch.
3. The poster says rain moves the event to Thursday. What would Yuki need to check, and why can't she decide from the poster alone?
Read the worked answer
She needs two pieces of information the poster does not give: whether it will actually rain, and whether Thursday at the same time conflicts with her tennis practice. The poster states the rain rule but not the time of the rain decision or her own schedule. So she cannot decide from the poster alone; she must check the weather decision and her Thursday practice time.