There were three rounds of 1:1 interviews. They asked standard puzzles. One puzzle involved 100 doors in a row, initially closed. On the first turn, every door was opened. On the second turn, doors at positions that are multiples of two were switched from their position. This continued for 100 turns. After the 100th turn, what doors were left open?

You have 100 doors in a row that are all initially closed. You make 100 passes by the doors, starting with the first door every time.

The first time through, you visit every door and toggle it (if the door is closed, you open it; if it's open, you close it). The second time, you only visit every 2nd door (door #2, #4, #6). The third time, every 3rd door (door #3, #6, #9), and so on, until you only visit the 100th door.

Question: What state are the doors in after the last pass? Which are open, and which are closed?

You find yourself in a duel with two other gunmen. You shoot with 33% accuracy, and the other two shoot with 100% and 50% accuracy, respectively. The rules of the duel are one shot per person per round. The shooting order is from worst shooter to best shooter, so you go first, the 50% guy goes second, and the 100% guy goes third.

Where or who should you shoot at in round 1?