In my house there are one thousand doors. There are one thousand guests. I tell the first guest to open all the doors. Then, I tell the second guest to open each second door. I tell the third to close every third door; if it's already closed, open it. Then I tell the fourth to do the same, and so on and so forth. After the thousandth guest has done the process, how many doors would be open, and how many would be closed?

if you can...which are the doors that are open?

easy one :D

Question

In my house there are one thousand doors. There are one thousand guests. I tell the first guest to open all the doors. Then, I tell the second guest to open each second door. I tell the third to close every third door; if it's already closed, open it. Then I tell the fourth to do the same, and so on and so forth. After the thousandth guest has done the process, how many doors would be open, and how many would be closed?

if you can...which are the doors that are open?

easy one :D

anonymous · Answer

Really? you must be filthy rich.

lgbasallote · Answer

oh yes i am >:))

blockcolder · Answer

If I remember correctly, this would entail counting the number of perfect squares less than 1000, right?

lgbasallote · Answer

darn..that fast already @_@ lol =))) i lose haha

blockcolder · Answer

The perfect square doors are the ones left open.