A scientist brings together 800 people in a field. He lined up the people (1 by 1) and told them all to sit down. He then explained the rules for the activity: "If I tap you on the shoulder, please change your position. If you're seated, you will stand - and if you're standing up, you'll sit down. On his first trip down the line of people, he tapped every single person. On his second trip down the line, he started with the second person and tapped every other person. On his third trip, he started with the third person and tapped every third person. He continued this pattern taking a total of 800 trips down the line of people.
1. At the end of the activity, how many people were standing?
2. Which ones were they? (1st, 2nd, 3rd, etc.