C25 Rule
"Take a random question. If you answer wrongly or exceed the time limit, you will be deducted 100 points. If you answer correctly, you will be rewarded 100 points."
"Out of the four people below, only one of them is telling the truth."
"A: I didn't kill him."
"B: I killed him."
"C: I killed him."
"D: I didn't kill him."
"Who is the murderer?"
The time limit was two minutes