plzzzzzzzzzzzzzzz help me im desperate here?

Question

a classroom had 25 lockers in a row. The first person to enter the room opened every locker. The second person closed every other locker beginning with the second locker. The third person started with the third locker and changed every third locker from open to closed or closed to open. This continued until 25 people passed through the room. which lockers would be open after the 25th person walked into the room? plz show work

Answer 1

The perfect squares (1, 4, 9, 16, 25) are open and the rest are closed.

The Nth person changes the state of the Nth, 2Nth, etc. lockers.  If the locker number has an even number of unique divisors, it ends up closed; odd, it ends up open.  A prime number has 2 divisors (including 1) and ends up closed; a product of 2 primes (like 6) has 4 divisors, etc.  Only a perfect square has an odd number of divisors.

Answer 2

I did this a little differently than the last person. I took it as the fourth person would open every fourth locker etc etc. So if that's correct than I think this is the answer. It is a lot of work and you should write it all out.

Your answer is lockers 1, 4, 9, 12, 14 and 16 would be open.

Answer 3

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25-first person, all lockers open
1 3 5 7 9 11 13 15 17 19 21 23 25-second person these lockers open
1 3,7,9,13,15,19,21,25-third person, these lockers open
1,3,9,11,13,21,25(4)
1,3,9,10,13,15,20,21(5)
1,3,9,11,13,15,17,20,21,23(6)
1,3,9,11,15,17,21,23(7)
1,3,9,11,21(8)
1,3,9,11,19,21(9)
1,3,9,11,19-(10)
1,3,9,11,19,23(11)
1,3,9,11,19,23,25(12)
1,3,9,11,19,23,25 (13)
1,3,9,11,19,23,25(14)
1,3,9,11,19,23,25(15)
1,3,9,11,19,23,25(16)
1,3,9,11,19,23,25(17)
1,3,9,11,19,23,25(18)
1,3,9,11,19,23,25(19)
1,3,9,11,19,23,25(20)
1,3,9,11,19,23,25(21)
1,3,9,11,19,23,25(22)
1,3,9,11,19,23,25(23)
1,3,9,11,19,23,25(24)
1,3,9,11,19,23,25(25)
write out all your numbers on a piece of paper and use numbers and symbols to indicate which locker gets changed for each person that passes through the room
write out the newest line of open lockers each time

it's a lot of work so i hope you're ready to write

i hope i did this right
but you might have to check it yourself

Answer 4

You've described a modified Sieve of Erasthones. The ones left open will be the squares up to 25

1 OOOOO OOOOO OOOOO OOOOO OOOO
2 OXOXO XOXOX OXOXO XOXOX OXOXO
3 OXXXO OOXXX OOOXX XOOOX XXOOO
4 OXXOO OOOXX OXOXX OOOOO XXOXO
5 OXXOX OOOXO OXOXO OOOOX XXOXX
6 OXXOX XOOXO OOOXO OOXOX XXOOX
7 OXXOX XXOXO OOOOO OOXOX OXOOX
8 OXXOX XXXXO OOOOO XOXOX OXOXX
9 OXXOX XXXOO OOOOO XOOOX OXOXX
10 OXXOX XXXOX OOOOO XOOOO OXOXX
11 OXXOX XXXOX XOOOO XOOOO OOOXX
12 OXXOX XXXOX XXOOO XOOOO OOOOX
13 OXXOX XXXOX XXXOO XOOOO OOOOX
14 OXXOX XXXOX XXXXO XOOOO OOOOX
15 OXXOX XXXOX XXXXX XOOOO OOOOX
16 OXXOX XXXOX XXXXX OOOOO OOOOX
17 OXXOX XXXOX XXXXX OXOOO OOOOX
18 OXXOX XXXOX XXXXX OXXOO OOOOX
19 OXXOX XXXOX XXXXX OXXXO OOOOX
20 OXXOX XXXOX XXXXX OXXXX OOOOX
21 OXXOX XXXOX XXXXX OXXXX XOOOX
22 OXXOX XXXOX XXXXX OXXXX XXOOX
23 OXXOX XXXOX XXXXX OXXXX XXXOX
24 OXXOX XXXOX XXXXX OXXXX XXXXX
25 OXXOX XXXOX XXXXX OXXXX XXXXO

1,4,9,16,25

Answer 5

water...hmmm, i'm wondering a water fairy of a few type, in which she's made from a mass body of water and also you'll be imaginitive with the way you want to structure her up and stuff it could be a drawing or made from clay and also you may beautify her with all kinds of issues found in water e.g. algae and so on or you are able to do a drawing of the sea even as that is tricky...emphasize how tricky and violent the water might want to be in such climate and so on...desire i have helped!!! cheers and good luck=]

Answer 6

it's confusing but I think it involves the use of algebra, try to apply algebraic equations to it

Answer 7

well i think u should show your work. i can help you but i wont answer it. try drawing it out

Answer 8

I dont know