This morning, when physics teacher Kieran Lynch was erasing his whiteboard, he became aware of a gruesome smudge that a spray of water could not remove. The only way for this to happen is for a student to touch the board. Four students had used the whiteboard that day, one from each grade, and they each did a problem from a different unit. Each of them also ate a different lunch. We interviewed each of the suspects to find out who was responsible. While we weren’t able to ascertain the character of every student we interviewed, their second person is known to value his integrity, they wouldn’t even lie to save themselves.
(Words in bold are the actual claims made by the students. Everything else is not important to the answer)
Recording #1 – 10:32:34 – You want to know about my physics class? I did a kinematics problem. It was pretty hard, but I did it on the board to show how I figured it out. By the way, I didn’t say anything this morning that would contradict itself if it were true. Don’t let people say otherwise.
The whiteboard? Good luck finding the other suspects. But if you can find him and ask him, the guy who did the torque problem will confess that he touched the board.
By the way, are you coming to the Outlook meeting? It’s tenth period today. It would be nice to have you there.
Anyway, I should get going so I can catch up with my friends. We’re going to the pizza place.
Recording #2 – 12:47:08 – School lunch today was great! The senior told me he loved it. I don’t know how he gets there so early. When I went to the math and logic club, he was already there.
This morning, the freshman whispered to me that everything he says is a lie. If that statement were true, it would mean that it’s false, but if it became false, then it could make itself true again. It’s a bit confusing to think about.
Oh, you’re investigating the whiteboard? If you ask the person who got pizza if I did it, he will definitely say I did. Don’t trust him. Me and only one other student only tell the truth, and there’s at least one person who always lies.
Recording #3 – 13:29:58 – There’s something I can tell you that might help you figure out the incident in physics. In the cafeteria, I saw someone working on a torque problem.
If you’re worried about false accounts, the situation is quite simple: everyone you talk to either always tells you the truth or always lies. Be careful, because two of us always lie. There’s one guy other than me that you can listen to; the sophomore told you the truth. Also, the second person you interviewed can tell lies. Finally, someone older than me can tell the truth. It won’t matter much, though. The people who need this won’t find out. By the time these interviews get published, everything in them will be a lie.
Recording #4- 14:20:20 – Wow, it got warm out here.
I’ve seen quite a lot having to do with this whiteboard situation. I saw the guy working on the circuit leave to get pizza. I think that the person who did the momentum problem is younger than the person who did the torque problem. Oh, and I heard from someone else in my grade that someone showed off a kinematics problem at the start of the math and logic club, but I wasn’t there.
I understand if you can’t trust everything I say. People younger than me have told you four relevant lies. I don’t know why they’re trying to make it so much harder for you.
Even if this investigation doesn’t pan out, maybe I’ll have someone write a feature on it for The Outlook. I go to every meeting.
Who touched the board? If you solve this, you’re ready for the AP exam.
THE ANSWER WILL BE REVEALED NEXT ISSUE.
