A farmer challenges an engineer, a physicist, and a mathematician to fence off the largest amount of area using the least amount of fence. The engineer made his fence in a circle and said it was the most efficient. The physicist made a long line and said that the length was infinite. Then he said that fencing half of the Earth was the best. The mathematician laughed at the others and with his design, beat the others. What did he do?
The mathematician made a small circular fence around himself and declared himself to be on the outside.
A group of campers have been on vacation so long, that they've forgotten the day of the week. The following conversation ensues.
Darryl: "What's the day? I dont think it is Thursday, Friday or Saturday."
Tracy: "Well that doesn't narrow it down much. Yesterday was Sunday."
Melissa: "Yesterday wasn't Sunday, tomorrow is Sunday."
Ben: "The day after tomorrow is Saturday."
Adrienne: "The day before yesterday was Thursday."
Susie: "Tomorrow is Saturday."
David: "I know that the day after tomorrow is not Friday."
If only one person's statement is true, what day of the week is it?