Day 2: 10:00 P.M.-11:00 P.M. - S2-E15
Question: If Jack jumps from the plane only four minutes before the bomb is going to detonate, how come he survives the radiation?
Day 2: 6:00 A.M.-7:00 A.M. - S2-E23
Question: Who is the woman seen with Kingsley near the end of the episode? At one point we see him reach for a knife, does he kill her?
Answer: Yes. At the end of the episode in question when it goes to split screen before the clock appears, one of the screens shows Kingsley stood in front of his desk with her lying on the floor.
Day 5: 11:00 PM - 12:00 AM - S5-E17
Question: Why was Audrey so desperate to ditch the tracker that was put on her car? Wouldn't it have made more sense for her to lead the people following her to the airport? She was meeting her father after all, and once the people back at CTU realised that they may have stopped being so suspicious.
Answer: If she allowed herself to be followed, there was no guarantee that her father's plane would touch down before Audrey and Jack got there. Once Jack got there, CTU tactical teams would've moved in and arrested them both.
Question: How did Sean and Erica know that wiping the servers would erase the files Chloe was downloading off the memory card? How did they know it was a self deleting (which doesn't exist) card and not just an SD card or similar that doesn't self delete?
Answer: Believe it or not, self-deleting drives do exist, but they're only used by agencies and governments. That means that Shaun and Erica would know that the only drive that Dubaku would have access to would be a self-deleting one.
Day 5: 6:00 AM - 7:00 AM - S5-E24
Question: How did Jack get kidnapped by the Chinese, beaten to a pulp and end up on a ship in the middle of the ocean in about 10 minutes?
Answer: He got a call pretending to be his daughter.
Answer: Because the bomb exploded in a depression in the Mojave desert, which contains the radiation.