significado de statement Riddles

A car thief, who had managed to evade the authorities in the past, unknowingly took the automobile that belonged to Detective Anderson. The detective wasted no time and spared no effort in discovering and carefully examining the available clues. He was able to identify four suspects with certainty that one of them was the culprit. The four make the statements below. From twelve of total statements, six are true and six false. Suspect A: 1. C and I have met many times before today. 2. B is guilty. 3. The car thief did not know it was the Detective's car. Suspect B: 1. D did not do it. 2. D's third statement is false. 3. I am innocent. Suspect C: 1. I have never met A before today. 2. B is not guilty. 3. D knows how to drive. Suspect D: 1. B's first statement is false. 2. I do not know how to drive. 3. A did it. Which one is the car thief?

A group of campers have been on vacation so long, that they've forgotten the day of the week. The following conversation takes place. Darryl: What's the day? I don't 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?

You're both in and outside of me; You guide me but don't ride me; I can make a statement with a tongue but no mouth. What am I?