I found this nice puzzle on math.stackexchange.com. I hadn't seen it before.
In a school hallway there are 100 closed lockers. 100 people walk through the hallway one after another.
The first person changes the state of every locker from closed to open,
The second person changes the state of every second locker, from open to closed,
The third person changes the state of every third locker, from open to closed or vice versa,
The fourth person changes the state of every fourth locker, from open to closed or vice versa,
and so on, right on until the hundreth person, who changes the state, open or closed, of every hundredth locker.
At the end which of the lockers are open?
Answer tomorrow.
The Locker Puzzle
I found this nice puzzle on math.stackexchange.com. I hadn't seen it before.
In a school hallway there are 100 closed lockers. 100 people walk through the hallway one after another.
The first person changes the state of every locker from closed to open,
The second person changes the state of every second locker, from open to closed,
The third person changes the state of every third locker, from open to closed or vice versa,
The fourth person changes the state of every fourth locker, from open to closed or vice versa,
and so on, right on until the hundreth person, who changes the state, open or closed, of every hundredth locker.
At the end which of the lockers are open?
Answer tomorrow.